SIGNIFICANCE OF NEGATIVE HISTORY IN NEUROLOGY.pptx

negative history in neurology
differential diagnosis
history taking and key points

1. SIGNIFICANCE OF NEGATIVE HISTORY IN NEUROLOGY DR PRAKARSH SHARMA SR NEUROLOGY GMC KOTA

2. CASE 1 A 7-year-old boy is being seen in the office for staring episodes . The parents state that the child's teacher called them into the school for a conference due to multiple episodes of his staring out into space and being unresponsive and unaware . These episodes lasted for about 10 seconds , and then he continued with his activity as though nothing happened. There was no confusion afterward. There was no urinary or bowel incontinence, hyperventilation, or motor activity. The parents state that they had noticed these episodes but just thought it was normal daydreaming . The patient is unaware of having these "spells." The pregnancy, delivery, and childhood have been normal. Immunizations are up to date, and vital signs are normal. The general physical examination and neurologic exam are normal. There are no episodes observed during the exam. • What is the most likely diagnosis? What is the best test to confirm the diagnosis? • What is the next step in therapy?

3. SEIZURE DISORDER Medical History No History of Head Trauma : Absence of significant head injuries, especially those resulting in loss of consciousness. No History of Central Nervous System (CNS) Infections : No history of meningitis, encephalitis, or other CNS infections. No History of Brain Tumors or Lesions : Absence of brain tumors, cysts, or other structural abnormalities. No History of Stroke or Transient Ischemic Attacks (TIA) : No previous cerebrovascular events. No History of Febrile Seizures : Absence of febrile seizures in childhood. No Family History of Seizure Disorders : No known family history of epilepsy or other seizure disorders.

4. Medication and Substance Use No Use of Epileptogenic Medications : Absence of medications known to lower seizure threshold (e.g., certain antidepressants, antipsychotics, antibiotics). No History of Alcohol or Drug Abuse : No history of excessive alcohol use, alcohol withdrawal, or use of illicit drugs known to cause seizures. No Recent Changes in Medication : No recent initiation or discontinuation of medications that could provoke seizures. Lifestyle Factors No Sleep Deprivation : No significant history of chronic sleep deprivation or irregular sleep patterns. No History of Significant Stress or Anxiety : Absence of extreme stress or anxiety that could precipitate seizures.

5. Medical Conditions No Metabolic or Electrolyte Imbalances : Absence of conditions like hypoglycemia, hyponatremia, hypocalcemia, or other metabolic disturbances. No History of Eclampsia : For women, no history of eclampsia or severe preeclampsia during pregnancy. Symptomatology No Unexplained Episodes of Loss of Consciousness : No history of unexplained fainting or loss of consciousness. No History of Unusual Movements or Behaviors : Absence of unexplained motor or behavioral phenomena that might suggest seizures. No Episodes of Sudden Onset Confusion or Memory Loss : No episodes of confusion, memory loss, or unresponsiveness.

6. Neurological Examination Normal Neurological Examination : No abnormalities on neurological exam, including motor and sensory function, reflexes, and coordination. No History of Migraine with Aura : Absence of migraines with aura, which can sometimes mimic or precipitate seizures. Diagnostic Results 19. Normal EEG Results : No abnormal findings on electroencephalogram (EEG) if performed previously. 20. Normal Neuroimaging : No abnormalities on brain MRI or CT scan.

7. Developmental and Psychiatric History No Developmental Delays or Disorders : Absence of developmental delays, intellectual disabilities, or autism spectrum disorders. No History of Psychiatric Disorders : No significant history of psychiatric conditions such as major depression, bipolar disorder, or schizophrenia. Differential Diagnoses No Features Suggestive of Non-Epileptic Events : Absence of symptoms suggesting syncope, cardiac arrhythmias, psychogenic non-epileptic seizures (PNES), or other conditions that can mimic seizures.

8. Differential diagnosis of seizures 1 . Syncope (Fainting) Precipitating Factors : Often related to standing, dehydration, or emotional stress. Prodromal Symptoms : Lightheadedness, sweating, nausea before loss of consciousness. Duration : Typically brief (seconds to minutes). Postictal State : Rapid recovery with no confusion or postictal symptoms.

9. CASE 2 A 27-year-old man is being seen in the emergency department (ED) for a seizure episode. He is one of the members on the marketing team, which was working at the office late at night preparing for a presentation the next day. He told his coworkers that he was not at all worried about the presentation. As he was practicing his part of the presentation, he suddenly stopped talking, stared at the wall, and slid off of his chair onto the floor . Both of his arms and legs suddenly began shaking uncontrollably with asynchronous movements of fluctuating intensity. He closed his eyes and complained about pain during the event. He remained responsive during the event and was heard begging, "Please stop, my arms and legs won't stop.. After the episode ended, he began mumbling incoherently. He was quickly taken to the ED by one of his coworkers. The patient denies incontinence of urine or stool. He states that he did not bite his tongue , and he suffered no injuries when he fell from the chair. He denies prior similar events and has no family history of epilepsy. He is in good health and takes no medications. He denies alcohol or drug use. On examination, his vital signs, general physical exam, and neurologic exam are all normal. • What is the most likely diagnosis? • What is the next diagnostic step? • What is the next best step in management?

10. 2 .Psychogenic Nonepileptic Seizures (PNES) Psychiatric History : Often associated with psychiatric disorders or history of trauma. Seizure Characteristics : May have more prolonged or fluctuating course, side-to-side head movements, pelvic thrusting, or vocalization. EEG Findings : Normal EEG during events.

11. 3.Transient Ischemic Attacks (TIA) Focal Neurological Deficits : Weakness, numbness, or speech difficulties. Duration : Symptoms usually last less than 24 hours. Risk Factors : History of cardiovascular disease, hypertension, diabetes. 4.Migraine with Aura Preceding Symptoms : Visual disturbances (e.g., flashing lights), sensory changes, speech difficulties. Headache : Often follows the aura phase, throbbing and unilateral. Duration : Aura typically lasts 5-60 minutes, headache can last hours.

12. 5 .Metabolic Disturbances Hypoglycaemia : Sweating, tremors, confusion, often related to insulin use or diabetes. Electrolyte Imbalance : Low sodium, calcium, or magnesium levels. Symptoms : Can include confusion, muscle twitching, or generalized weakness. 6. Cardiac Arrhythmias Palpitations : Sensation of irregular heartbeat. Syncope or Near Syncope : Often sudden with no warning. ECG Findings : May show abnormal heart rhythms.

13. 7 .Movement Disorders Tremors or Tics : Rhythmic or repetitive movements. Dystonia : Sustained muscle contractions causing twisting and repetitive movements. Parkinson's Disease : Resting tremor, bradykinesia, rigidity. 8. Intoxication or Withdrawal Alcohol or Drug Use : Recent history of substance use or withdrawal. Symptoms : Agitation, tremors, hallucinations (in case of withdrawal).

14. Work-Up Diagnostic Tools History and Physical Examination : Detailed patient history, including triggers, frequency, and description of episodes. Blood Tests : To check for metabolic or systemic causes (e.g., glucose, electrolytes, liver and kidney function). Neuroimaging : MRI or CT scan to identify structural abnormalities. Electroencephalogram (EEG) : To detect abnormal electrical activity in the brain. Cardiac Evaluation : ECG, Holter monitor, or event recorder for suspected cardiac arrhythmias. Psychiatric Evaluation : For suspected psychogenic non-epileptic seizures or panic attacks. Sleep Studies : For suspected sleep disorders.

15. Negative history in Headache Medical History No Chronic Headache Disorders : Absence of a diagnosis of chronic headache disorders such as migraine, tension-type headache, or cluster headache. No Recent Head Trauma : No history of recent head injuries or trauma that could contribute to headaches. No Neurological Disorders : No diagnosed neurological conditions, such as epilepsy, brain tumors, or multiple sclerosis. No History of Brain Infections : Absence of conditions like meningitis or encephalitis. No Significant Comorbidities : Lack of conditions such as hypertension, diabetes, or sleep disorders that can contribute to headaches. Family History No Family History of Headache Disorders : No family history of migraines or other hereditary headache conditions.

16. Lifestyle Factors No Substance Abuse : No history of excessive alcohol or drug use, including caffeine. Healthy Sleep Patterns : Consistent and adequate sleep without significant disturbances or sleep disorders. Balanced Diet : No dietary triggers, such as irregular meal patterns, dehydration, or specific food sensitivities. Psychological Factors No Significant Stress or Anxiety : Absence of chronic stress, anxiety, or depression, which can be associated with headache onset. No History of Mental Health Disorders : No diagnosed mental health conditions that might contribute to headaches.

17. Environmental Factors No Exposure to Headache Triggers : No regular exposure to environmental triggers like strong odors, bright lights, or loud noises. Medication Use No Overuse of Analgesics : No history of overusing pain medications, which can lead to rebound headaches. No Use of Headache-Inducing Medications : Absence of medications known to potentially cause headaches as a side effect (e.g., nitrates, hormone replacement therapy)

18. A 24-year-old woman is being seen in the office for worsening headaches. She says the headaches began 12 years ago, when she was in grade school, and the patient remembers missing school because of her headaches. She has never seen a physician for this problem. Typically, she gets one of these headaches four or five times per month. She anticipates the onset of a headache when she experiences flashing lights and zigzag lines in both eyes . A pounding headache starts about 30 minutes later around one eye and temple. There is extreme nausea and occasional vomiting. If possible, she goes into a quiet, dark room to rest. Generally, the headache lasts 6 to 12 hours , but the patient feels tired and listless for the next 12 to 24 hours. The patient feels that the headaches worsen with her menstrual cycle , and she notices that certain foods, especially red wine, can exacerbate her headache. Her blood pressure (BP) is 110/70 mm Hg and heart rate (HR) is 80 beats per minute. Her mental status is normal. Her general and neurologic examinations, including pupil and fundoscopic exams, are normal. She reports that her mother has similar episodes .• What is the most likely diagnosis?• What is the next diagnostic step?• What is the best therapy for this condition?

19. Differentials of headache PRIMARY HEADACHE 1.Migraine Characteristics : Unilateral, throbbing pain, often accompanied by nausea, vomiting, and sensitivity to light and sound. Duration : 4-72 hours. Triggers : Stress, certain foods, hormonal changes, sleep disturbances. Aura : Visual disturbances or other neurological symptoms in some cases.

20. 2. Tension-Type Headache Characteristics : Bilateral, pressing or tightening pain, mild to moderate intensity. Duration : 30 minutes to 7 days. Triggers : Stress, muscle tension, poor posture. Associated Symptoms : Usually no nausea or vomiting, may have mild photophobia or phonophobia.

21. 3.Cluster Headache Characteristics : Severe, unilateral pain, often around the eye, accompanied by autonomic symptoms like tearing, nasal congestion, and eyelid swelling. Duration : 15 minutes to 3 hours. Pattern : Occurs in clusters, typically at the same time of day or night, lasting weeks to months with periods of remission.

22. SECONDARY HEADACHE 1.Sinusitis Characteristics : Pain over the affected sinus (frontal, maxillary), pressure or fullness. Associated Symptoms : Nasal congestion, purulent nasal discharge, fever. 2.Medication Overuse Headache Characteristics : Chronic, daily headache, often worsened by medication. History : Frequent use of analgesics or headache medications. 3.Cervicogenic Headache Characteristics : Unilateral pain originating in the neck, radiating to the head. Triggers : Neck movement or sustained awkward positions. Associated Symptoms : Restricted neck movement.

23. 4. Subarachnoid Hemorrhage Characteristics : Sudden, severe "thunderclap" headache. Associated Symptoms : Nausea, vomiting, neck stiffness, altered consciousness. History : Often no prior history, may occur after exertion or trauma. 5.Temporal Arteritis (Giant Cell Arteritis) Characteristics : Unilateral or bilateral throbbing headache, usually in older adults. Associated Symptoms : Scalp tenderness, jaw claudication, visual disturbances. Lab Findings : Elevated ESR and CRP. 6.Brain Tumor Characteristics : Progressive headache, worse in the morning or with Valsalva maneuvers. Associated Symptoms : Neurological deficits, seizures, personality changes. Imaging : MRI or CT scan showing mass.

24. 7.Idiopathic Intracranial Hypertension (Pseudotumor Cerebri ) Characteristics : Generalized headache, worse with straining, may have visual symptoms. Associated Symptoms : Papilledema, transient visual obscurations. Risk Factors : Young, obese women. 8.Meningitis Characteristics : Severe, generalized headache. Associated Symptoms : Fever, neck stiffness, altered mental status, photophobia. History : Recent infection, immunocompromised state. Diagnostic Tests : Lumbar puncture showing elevated WBCs, protein, and low glucose. 9.Trigeminal Neuralgia Characteristics : Brief, intense, electric shock-like pain in the distribution of the trigeminal nerve. Triggers : Touch, chewing, talking, cold air. Duration : Seconds to minutes, recurrent episodes.

25. PERIPHERAL NEUROPATHIES Medical History No Diabetes : Absence of diabetes mellitus, which is a common cause of peripheral neuropathy. No Autoimmune Diseases : Lack of autoimmune disorders such as lupus, rheumatoid arthritis, or Guillain-Barré syndrome. No History of Infections : No history of infections like HIV, hepatitis, Lyme disease, or syphilis that can lead to neuropathy. No Exposure to Toxins : No history of exposure to toxins such as heavy metals (lead, mercury) or industrial chemicals. No Nutritional Deficiencies : Absence of deficiencies in essential vitamins and nutrients, particularly B vitamins (B1, B6, B12), vitamin E, and niacin. No Chronic Kidney Disease : Absence of renal insufficiency or chronic kidney disease. No Thyroid Dysfunction : No history of thyroid disorders, such as hypothyroidism or hyperthyroidism.

26. Lifestyle Factors No Alcohol Abuse : No history of chronic alcohol abuse, which can lead to alcoholic neuropathy. No Smoking : Absence of smoking, which can contribute to vascular problems and neuropathy. Medication Use No Neurotoxic Medications : No use of medications known to cause neuropathy, such as certain chemotherapeutic agents, antiretrovirals, or isoniazid. No History of Drug Abuse : No history of recreational drug use that can lead to neuropathy. Family History No Family History of Neuropathy : No family history of hereditary neuropathies such as Charcot-Marie-Tooth disease. Occupational and Environmental Factors No Occupational Hazards : No history of repetitive stress or vibration exposure, which can cause entrapment neuropathies like carpal tunnel syndrome.

27. No Prolonged Pressure : No history of prolonged pressure on nerves due to immobilization or use of certain equipment. Symptomatology No Symptoms of Neuropathy : Absence of symptoms such as numbness, tingling, burning pain, muscle weakness, or loss of coordination. Normal Physical Examination : No signs of neuropathy on neurological examination, such as diminished reflexes, muscle atrophy, or sensory deficits. Evaluation Results Normal Blood Tests : Normal blood glucose levels, thyroid function tests, kidney function tests, and vitamin levels. Normal Electrophysiological Studies : Normal nerve conduction studies and electromyography (EMG). No Abnormal Findings on Imaging : Normal MRI or CT scans showing no structural causes for neuropathy.

28. DIFFERENTIAL DIAGNOSIS OF NEUROPATHIES DIABETIC NEUROPATHY History : Long-standing diabetes mellitus. Symptoms : Burning pain, tingling, numbness, particularly in the feet and hands (stocking-glove distribution). Complications : Foot ulcers, Charcot joints. ALCOHOLIC NEUROPATHY History : Chronic alcohol abuse. Symptoms : Pain, tingling, numbness, muscle weakness, and cramping, particularly in the lower extremities. NUTRITIONAL DEFICIENCIES : Often associated with deficiencies in thiamine (B1) and other B vitamins. Deficiency Types : Vitamin B12, B1 (thiamine), B6 (pyridoxine), E, and niacin. Symptoms : Numbness, tingling, weakness, balance issues. History : Poor diet, malabsorption syndromes, bariatric surgery.

29. AUTOIMMUNE DISEASES Diseases : Guillain-Barré syndrome, lupus, rheumatoid arthritis, Sjogren's syndrome. Symptoms : Rapid onset of weakness, often ascending from the legs; numbness, tingling, pain. Associated Signs : Generalized inflammation, other systemic symptoms. INFECTIOUS NEUROPATHIES Diseases : HIV, Lyme disease, syphilis, leprosy. Symptoms : Vary depending on the infection; can include pain, numbness, weakness. History : Recent or chronic infections, tick bites, travel history. TOXINS AND DRUGS Toxins : Heavy metals (lead, mercury, arsenic), industrial chemicals. Drugs : Chemotherapeutic agents, antiretrovirals, isoniazid, metronidazole. Symptoms : Sensory and motor deficits, pain, weakness. History : Occupational exposure, medication history.

30. HEREDITARY NEUROPATHIES Diseases : Charcot-Marie-Tooth disease, hereditary sensory and autonomic neuropathies. Symptoms : Gradual onset of symptoms, often beginning in childhood or adolescence; foot deformities, muscle wasting. Family History : Positive family history of similar symptoms. METABOLIC DISORDERS Diseases : Uremic neuropathy (chronic kidney disease), hypothyroidism. Symptoms : Sensory and motor deficits, often in a distal symmetric pattern. History : Chronic kidney disease, thyroid dysfunction.

31. PARANEOPLASTIC NEUROPATHIES Associated with Cancer : Often associated with small cell lung cancer, lymphoma, or other malignancies. Symptoms : Progressive sensory and motor deficits, sometimes rapidly worsening. Associated Signs : Weight loss, night sweats, other cancer-related symptoms. COMPRESSIVE AND ENTRAPMENT NEUROPATHIES Examples : Carpal tunnel syndrome, ulnar neuropathy, tarsal tunnel syndrome. Symptoms : Pain, numbness, and tingling in the distribution of the affected nerve; muscle weakness in severe cases. History : Repetitive stress or injury, specific positional triggers.

32. PARKINSONISM Medical History No Family History of Parkinsonism or Related Disorders : Absence of a family history of parkinsonism, Parkinson’s disease, or other related movement disorders. No Prior Neurological Disorders : No history of other neurological conditions such as essential tremor, multiple system atrophy (MSA), progressive supranuclear palsy (PSP), or corticobasal degeneration (CBD). No History of Stroke or Cerebrovascular Disease : Absence of stroke or other cerebrovascular events that could cause vascular parkinsonism. No History of Head Trauma : Lack of significant head injuries or repeated head trauma (e.g., from contact sports or accidents). No History of Encephalitis : Absence of viral or post-infectious encephalitis. No Exposure to Neurotoxins : No history of exposure to toxins such as MPTP (a neurotoxin that can cause parkinsonism) or heavy metals.

33. Medication and Substance Use No Use of Dopamine-Blocking Medications : No history of taking medications that can induce parkinsonism, such as antipsychotics (e.g., haloperidol, risperidone), antiemetics (e.g., metoclopramide), or other drugs that block dopamine receptors. No History of Illicit Drug Use : Absence of drug use that could lead to secondary parkinsonism. Symptomatology No Resting Tremor : Absence of the characteristic resting tremor of parkinsonism. No Bradykinesia : No evidence of bradykinesia, or slowness of movement. No Rigidity : Absence of muscle stiffness or rigidity. No Postural Instability : No issues with balance or frequent falls. No Gait Abnormalities : No shuffling gait or reduced arm swing. No Dystonia or Dyskinesia : Absence of involuntary muscle contractions (dystonia) or abnormal, uncontrolled movements (dyskinesia

34. Cognitive and Psychological Factors No Cognitive Decline : Absence of cognitive impairment or dementia. No Depression or Anxiety : Lack of significant mood disorders, which can be associated with parkinsonism. Autonomic Symptoms No Autonomic Dysfunction : No issues with autonomic functions such as orthostatic hypotension, constipation, urinary incontinence, or excessive sweating. Sleep Disorders No REM Sleep Behavior Disorder : Absence of REM sleep behavior disorder, which involves acting out dreams.

35. Evaluation Results Normal Neurological Examination : No signs of the characteristic motor symptoms of parkinsonism (tremor, rigidity, bradykinesia, postural instability). Normal DaTscan or PET Scan : No abnormalities in dopamine transporter imaging studies. Normal Response to Levodopa : If trialed, no significant improvement with levodopa, which is often seen in idiopathic Parkinson's disease. Differential Diagnoses No Features Suggesting Alternative Diagnoses : Absence of symptoms or signs suggesting other conditions that can mimic parkinsonism, such as essential tremor, normal pressure hydrocephalus, or drug-induced parkinsonism. No Systemic Illnesses : Absence of systemic illnesses that could lead to secondary parkinsonism, such as Wilson's disease or hypothyroidism.

36. DIFFERENTIAL SPECTRUM 1. Parkinson's Disease (PD) Characteristics : Resting tremor, bradykinesia, rigidity, postural instability. Course : Progressive, often asymmetric onset. Response to Levodopa : Typically good. 2. Drug-Induced Parkinsonism Medications : Antipsychotics (e.g., haloperidol, risperidone), antiemetics (e.g., metoclopramide), calcium channel blockers, some antidepressants. Characteristics : Symmetrical symptoms, history of medication use. Course : Symptoms may improve after discontinuing the offending drug.

37. 3. Multiple System Atrophy (MSA) Characteristics : Parkinsonism plus autonomic dysfunction (orthostatic hypotension, urinary incontinence), cerebellar signs (ataxia), and corticospinal tract signs. Course : Rapid progression, poor response to levodopa 4. Progressive Supranuclear Palsy (PSP) Characteristics : Early postural instability and falls, vertical gaze palsy, axial rigidity, pseudobulbar palsy. Course : Rapid progression, poor response to levodopa. 5. Corticobasal Degeneration (CBD) Characteristics : Asymmetric parkinsonism, apraxia, cortical sensory deficits, myoclonus, alien limb phenomenon. Course : Progressive, poor response to levodopa.

38. 6. Lewy Body Dementia (LBD) Characteristics : Parkinsonism, early dementia, visual hallucinations, fluctuating cognitive impairment. Course : Progressive, poor response to levodopa. 7. Vascular Parkinsonism Characteristics : Lower body parkinsonism (gait difficulties, rigidity), history of strokes or cerebrovascular disease. Imaging : Evidence of cerebrovascular disease on MRI or CT. Course : Stepwise progression, poor response to levodopa. 8. Normal Pressure Hydrocephalus (NPH) Characteristics : Triad of gait disturbance, urinary incontinence, and cognitive impairment. Imaging : Enlarged ventricles on MRI or CT. Course : Symptoms may improve with shunting.

39. 9. Wilson's Disease Characteristics : Young onset (usually under 40), hepatic dysfunction, psychiatric symptoms, Kayser-Fleischer rings in the eyes. Diagnosis : Low serum ceruloplasmin, high urinary copper excretion. Course : Treatable with chelating agents. 10. Essential Tremor (ET) Characteristics : Action tremor (worsens with movement), typically bilateral and symmetric, may involve head and voice. Course : Often family history of similar tremor. Response to Alcohol : Tremor often improves with alcohol consumption.

40. 11. Dopa-Responsive Dystonia Characteristics : Childhood or adolescent onset, diurnal variation (symptoms worse later in the day), dystonia. Response to Levodopa : Dramatic improvement with low doses of levodopa. 12. Huntington's Disease Characteristics : Chorea, psychiatric symptoms, cognitive decline, family history. Genetic Testing : CAG repeat expansion in the HTT gene.

41. STROKE Medical History No History of Hypertension : Absence of a diagnosis or treatment for high blood pressure. No History of Diabetes Mellitus : Absence of a diagnosis or treatment for diabetes. No History of Heart Disease : No history of coronary artery disease, atrial fibrillation, heart failure, or other cardiac conditions. No History of Previous Stroke or Transient Ischemic Attack (TIA) : No prior episodes of stroke or TIA. No History of Hyperlipidemia : No diagnosis or treatment for high cholesterol or triglycerides. No History of Peripheral Artery Disease : Absence of a diagnosis of peripheral artery disease.

42. Lifestyle Factors No Smoking : Absence of current or past tobacco use. No Excessive Alcohol Use : No history of excessive alcohol consumption or alcohol use disorder. No Illicit Drug Use : No history of using drugs that increase stroke risk, such as cocaine or amphetamines. Family History No Family History of Stroke or Cardiovascular Disease : Absence of a family history of stroke, heart disease, or other cardiovascular conditions. Medication Use No Use of Oral Contraceptives or Hormone Replacement Therapy : Absence of use of these medications, especially in smokers or women over 35. No Use of Anticoagulants or Antiplatelet Agents : No history of taking medications that could indicate or affect stroke risk (unless prescribed for other conditions without incidents of stroke).

43. Symptomatology No Sudden Onset of Neurological Symptoms : Absence of sudden weakness, numbness, or paralysis, particularly on one side of the body. No Sudden Speech Difficulties : No history of sudden difficulty speaking, understanding speech, or slurred speech. No Sudden Vision Problems : Absence of sudden vision loss or double vision. No Sudden Severe Headache : No history of sudden, severe headache with no known cause. No Sudden Dizziness or Balance Issues : Absence of sudden loss of balance or coordination. 18.No History of Migraines with Aura : Absence of migraines with aura, which can increase stroke risk in some individuals. 19.No History of Blood Disorders : Absence of conditions such as sickle cell disease, clotting disorders, or other hematological conditions.

44. DIFFERENTIAL SPECTRUM 1. TRANSIENT ISCHEMIC ATTACK (TIA) Characteristics : Temporary neurological deficits that resolve within 24 hours. Symptoms : Similar to stroke but transient; may include weakness, numbness, speech difficulties, vision changes. 2. SEIZURES Characteristics : Sudden onset of neurological symptoms, postictal confusion. Symptoms : Motor or sensory symptoms, altered consciousness, automatisms. Postictal State : Confusion or drowsiness following the event. 3 . MIGRAINE WITH AURA Characteristics : Gradual onset of neurological symptoms followed by headache. Symptoms : Visual disturbances (e.g., scintillating scotoma), sensory changes, speech difficulties. History : Often a history of similar episodes.

45. 4. HYPOGLYCEMIA Characteristics : Low blood glucose levels causing neurological symptoms. Symptoms : Confusion, weakness, seizures, altered consciousness. Resolution : Symptoms improve with glucose administration. 5. BRAIN TUMOR Characteristics : Gradual onset of symptoms, progressive worsening. Symptoms : Focal neurological deficits, headache, seizures. Imaging : Mass effect on MRI or CT. 6. MULTIPLE SCLEROSIS (MS) Characteristics : Demyelinating disease with episodes of neurological deficits. Symptoms : Visual disturbances, sensory changes, motor weakness, often with relapsing-remitting course. History : Previous episodes of neurological symptoms.

46. 7. BELL'S PALSY Characteristics : Sudden onset of facial paralysis. Symptoms : Unilateral facial weakness, inability to close one eye, drooping mouth. Distinguishing Factor : Involves only the facial nerve; other neurological functions are intact. 8. VESTIBULAR DISORDERS Examples : Vestibular neuritis, labyrinthitis, benign paroxysmal positional vertigo (BPPV). Symptoms : Sudden onset of vertigo, dizziness, balance issues. Distinguishing Factor : Lack of other focal neurological deficits. 9. CONVERSION DISORDER (FUNCTIONAL NEUROLOGICAL SYMPTOM DISORDER) Characteristics : Neurological symptoms without an organic cause, often stress-related. Symptoms : Variable presentation, including weakness, paralysis, sensory changes. History : Psychological stressors or history of psychiatric disorders.

47. 10. ENCEPHALITIS Characteristics : Inflammation of the brain, often infectious. Symptoms : Fever, headache, confusion, seizures, focal neurological deficits. History : Recent infection or immunocompromised state. 11. INTRACRANIAL HEMORRHAGE Types : Subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH). Symptoms : Sudden severe headache (thunderclap headache), focal deficits, altered consciousness. Risk Factors : Hypertension, aneurysms, anticoagulant use. Imaging : Blood visible on CT or MRI. 12. HYPERTENSIVE ENCEPHALOPATHY Characteristics : Severe hypertension with neurological symptoms. Symptoms : Headache, confusion, seizures, visual disturbances. Resolution : Improvement with blood pressure control.

48. 13. CENTRAL NERVOUS SYSTEM (CNS) INFECTION Examples : Meningitis, abscess. Symptoms : Fever, headache, neck stiffness, altered consciousness, focal deficits. History : Recent infection, immunosuppression

49. DEMENTIA Medical History No History of Traumatic Brain Injury : Absence of significant head injuries or repeated head trauma. No History of Stroke or Transient Ischemic Attack (TIA) : No prior cerebrovascular events that could contribute to vascular dementia. No History of Brain Tumors : Absence of brain tumors or other intracranial masses. No History of Chronic Alcohol Abuse : Lack of chronic excessive alcohol consumption. No History of Psychiatric Disorders : Absence of major psychiatric conditions such as severe depression, bipolar disorder, or schizophrenia. No History of Neurological Disorders : No diagnosis of Parkinson's disease, Huntington's disease, multiple sclerosis, or other chronic neurological conditions. No History of Infections : Absence of infections that can affect the brain, such as HIV, syphilis, or prion diseases.

50. Medication Use No Use of Cognitive Impairing Medications : No history of long-term use of medications known to affect cognition, such as anticholinergics, sedatives, or certain psychiatric medications. No History of Drug Abuse : Absence of illicit drug use that could impact cognitive function. Family History No Family History of Dementia or Neurodegenerative Diseases : Absence of a family history of Alzheimer's disease, frontotemporal dementia, or other hereditary neurodegenerative conditions. Symptomatology No Memory Loss : Absence of short-term or long-term memory deficits. No Difficulty with Executive Function : No issues with planning, organizing, or problem-solving. No Language Problems : No problems with speaking, understanding, reading, or writing.

51. No Visuospatial Difficulties : Absence of problems with spatial awareness, recognizing faces, or navigating familiar places. No Behavioral Changes : No significant changes in personality, mood, or behavior. No Difficulty with Daily Activities : No problems with performing activities of daily living (ADLs) such as dressing, bathing, or managing finances. COGNITIVE AND PSYCHOLOGICAL FACTORS No Cognitive Decline Noted by Others : Absence of reported cognitive decline by family members, friends, or colleagues. No Depression or Anxiety : Lack of significant mood disorders that could mimic or contribute to cognitive symptoms. No Symptoms Suggesting Alternative Diagnoses : Absence of symptoms suggesting conditions that can mimic dementia, such as delirium, normal pressure hydrocephalus, or chronic subdural hematoma.

52. DIFFERENTIAL DIAGNOSIS 1. ALZHEIMER'S DISEASE (AD ) Characteristics : Gradual onset and progressive memory loss, language difficulties, and disorientation. Key Features : Amyloid plaques and neurofibrillary tangles on neuropathology. 2. VASCULAR DEMENTIA (VAD) Characteristics : Stepwise cognitive decline following cerebrovascular events. Key Features : History of stroke or transient ischemic attacks, often associated with hypertension or other vascular risk factors. Imaging : Evidence of infarcts or extensive white matter lesions on MRI or CT. 3. LEWY BODY DEMENTIA (LBD) Characteristics : Fluctuating cognition, visual hallucinations, parkinsonism. Key Features : Lewy bodies (alpha-synuclein aggregates) in the brainstem and cortex.

53. 4. FRONTOTEMPORAL DEMENTIA (FTD) Characteristics : Early changes in personality, behavior , and language. Key Features : Frontal and temporal lobe atrophy on imaging. Subtypes : Behavioral variant FTD, primary progressive aphasia, semantic variant. 5. PARKINSON'S DISEASE DEMENTIA (PDD) Characteristics : Dementia occurring in the context of established Parkinson’s disease. Key Features : Parkinsonism with dementia appearing more than a year after motor symptoms. 6. NORMAL PRESSURE HYDROCEPHALUS (NPH) Characteristics : Triad of gait disturbance, urinary incontinence, and cognitive impairment. Key Features : Enlarged ventricles on MRI or CT, with normal CSF pressure. 7. HUNTINGTON'S DISEASE Characteristics : Genetic disorder with motor abnormalities (chorea), psychiatric symptoms, and cognitive decline. Key Features : CAG repeat expansion in the HTT gene.

54. 8. CREUTZFELDT-JAKOB DISEASE (CJD) Characteristics : Rapidly progressive dementia with myoclonus, ataxia. Key Features : Prion disease; abnormal prion protein on CSF analysis (14-3-3 protein), MRI showing cortical ribboning. 9. CHRONIC TRAUMATIC ENCEPHALOPATHY (CTE) Characteristics : Cognitive decline and behavioral changes linked to repeated head trauma. Key Features : Tau protein deposition in the brain. 10. ALCOHOL-RELATED DEMENTIA (WERNICKE-KORSAKOFF SYNDROME) Characteristics : Cognitive impairment related to chronic alcohol abuse. Key Features : Thiamine deficiency, often with Wernicke's encephalopathy (confusion, ataxia, ophthalmoplegia). 11. VITAMIN B12 DEFICIENCY Characteristics : Cognitive decline, often with peripheral neuropathy. Key Features : Low serum B12 levels, macrocytic anemia .

55. 12. HYPOTHYROIDISM Characteristics : Cognitive impairment, lethargy, depression. Key Features : Elevated TSH, low free T4. 13. DEPRESSION (PSEUDODEMENTIA) Characteristics : Cognitive impairment due to severe depression. Key Features : Reversible with treatment of depression, more apparent lack of effort on cognitive testing.

56. SUMMARY In summary, while positive symptoms often dominate the clinical picture, negative history in neurology is equally valuable. It helps in refining diagnostic possibilities, guiding treatment decisions, assessing risk, and providing a more comprehensive understanding of the patient's condition. Therefore, neurologists rely on both positive and negative historical information to provide optimal care for their patients.

57. References Bradely and daroff textbook neurology Harrison 20 th edition textbook medicine Case files neurology Aruchamy clinical manual pediatrics

58. THANK YOU