Cerebellum disorder include hereditary and acquired.pptx

cerebellar disorder

1. ﺔﻳﻧﻻﺩﻳﺻﻟﺍﻭ ﺔﻳﺑﻁﻟﺍ ﻡﻭﻠﻌﻠﻟ ﺎﻧﻳﺳ ﻥﺑﺍ ﺔﻌﻣﺎﺟ ﺏﻁﻟﺍ ﺔﻳﻠﻛ ﻲﻧﻁﺎﺑﻟﺍ ﺏﻁﻟﺍ ﻉﺭﻓ Cerebellum and Vestibular system 5 TH stage of students at Ibn sina college of Medicine By Lecturer Dr. Mahmood Abdul Munem Neurologist at Ibn Sina university. M.B.CH.B/F.I.C.M

2. Objectives: At the end of this lecture the students will be able to: Understand the basic knowledge for Cerebellum and Vestibular system Recognise the Signs and symptoms of Cerebellar and Vestibular dysfunction Identify causes of Cerebellar and Vestibular diseases.

3. Content Cerebellum Anatomy Cerebellar function Causes of Cerebellar diseases Vestibular system anatomy Symptoms and signs of Vestibular system disorders Most common disease of vestibular system

4. Cerebellum

5. The Cerebellum Anatomy cerebellum is divided into three major lobes by transverse fissures: The flocculonodular lobe( vestibulocerebellum ) The anterior lobe. The posterior lobe. more functionally useful method of describing the cerebellum is based on its longitudinal zone patterns and their different connections into: Vermis Hemisphers

6. Connection to Brain

7. Activity نشاط رقم 1 Why cerebellar lesion affect the same side of the body?

8. Function The cerebellum, principally a motor organ, is responsible for: The regulation and control of muscular tone The control of gait The coordination of movement by synergistic action, especially voluntary movement. Its main role is to orchestrate the force, rate, sequence and timing of muscular contraction required to produce steady volitional movement that are generated in the cerebral hemispheres. Maintains equilibrium. Equilibrium is the ability to maintain the orientation of the body and its parts in relation to the external space. The flocculonodular lobe receives special proprioceptive impulses from the vestibular nuclei. The processes of procedural (skill) learning reside primarily in the motor system, and specifically in the cerebellum.

9. Defective muscular control resulting in irregular and clumsiness of movement that is not the result of muscular weakness . Ataxia can affect eye movement, speech, limbs, trunk, stance (the standing posture) and gait. There are three types of ataxia: Cerebellar ataxia Vestibular ataxia Sensory ataxia Cerebellar ataxia divided into two types: truncal ataxia due to disequilibrium and limb ataxia due to incoordination Ataxia

10. Signs of cerebellar ataxia Specific cerebellar signs (signs of incoordination): disturbance in force, rate, sequence, direction, or timing of movement. (Hemispheric lesion) 1- Intention tremor : as approaches the target, oscillation appears because the irregularities in rate and force of movements pronounced during termination of movement. 2- Dyssynergia: Dyssynergestic movements ( fragmentations) 3- Dysdiadochokinesia : clumsiness in performing alternating movement. 4- Dysmetria (past pointing): irregular errors in the distance and force of limb movements. 5- Impairment of the check reflex (impaired rebound ): impairment of the ability to check the force of muscular contraction.

11. B) Nonspecific cerebellar signs: 1- Hypotonia . Hypotonia accompanies acute cerebellar hemispheric lesions and is seen less often with chronic lesions. 2- Scanning and staccato dysartheria . 3- Ocular movement : Ocular movements may be impaired as a result of cerebellar disease. Nystagmus. Gaze impairment: Patients with cerebellar lesions are unable to hold lateral positions of gaze. 4- Ataxic gait Symptomatic cerebellar lesions universally impair the gait and stance (the standing posture). Vermis lesion : gait ataxia and truncal ataxia due to disequilibrium.(Wide base gait) hemispheres lesion : the gait is drunken like gait with veering to one side in unilateral lesion and to both sides in bilateral cerebellar lesion. 5- Pendular reflexes

12. Signs of cerebellar Lesion Midline cerebellar lesion Hemisphere lesion Broad base gait. Hypotonia. Vertical nystagmus Nystagmus. Head and trunk titubation Drunken like gait Dysartheria (left paravermal lesion). Incoordination signs

13. Causes of cerebellar ataxia A. Sudden: Vascular (cerebellar infarction or hemorrhage) B . Acute and Subacute 1. Infection: cerebellitis 2. Metabolic: drugs (Carbamazepine), Wernicke's encephalopathy 3. Inflammatory and autoimmune disease C. Chronic 1- Acquired deficit : 2- Hereditary D rugs: phenytoin posterior fossa malformations A lcoholic cerebellar degeneration Wilson’s disease MS ataxia-telangiectasia T umors, paraneoplastic. hypothyroidism hereditary spinocerebellar ataxias(FA) Gluten ataxia

14. Friedreich ataxia is progressive cerebellar ataxia and accounts for approximately one half of all cases of hereditary ataxia. Friedreich ataxia is an autosomal recessive spinocerebellar disorder, which has a slow but relentlessly degenerative course. The current hypothesis is that frataxin is a mitochondrial protein and a defect in its action may result in abnormal accumulation of iron in mitochondria , leading to excess production of free radicals, which then results in cellular damage and death. (long tracts of the dorsal columns, pyramidal system, and peripheral nerves). Prevalence is 1-2 per 100,000. Men and women are affected equally . Women have a significantly better prognosis than men. Friedreich ataxia

15. Clinical manifestations usually begin at aged 8-15 years. Ataxia of gait is the most frequent presenting symptom. The hands usually become clumsy months or years after the gait disorder, and dysarthric speech appears after the arms are involved. pes cavus and kyphoscoliosis precede the neurologic symptoms. In others, these follow by several years. Deep tendon reflexes are absent . Plantar responses are extensor . Distal wasting . Impaired vibration and proprioception sense. Diabetes mellitus occurs in 10% of patients with Friedreich ataxia. Heart disease is present in at least two thirds of patients with Friedreich. Significant sensorineural deafness occurs in 10% of persons with Friedreich ataxia.

16. Diagnosis Confirmation of the diagnosis by DNA testing is recommended for all patients in whom Friedreich ataxia is clinically suspected. MRI findings are normal or show mild cerebellar atrophy (usually observed late in the disease). The cervical spinal cord often is atrophied . Echocardiogram exhibits evidence of hypertrophic cardiomyopathy in approximately 40% of patients. Electrocardiogram is abnormal in approximately two-thirds of patients.

17. Treatment /Mortality/Morbidity Medical Care: No treatment to date has been shown to delay, stop, or reverse the progression of Friedreich ataxia is known. Diabetes must be managed. Cardiac failure and arrhythmias should be treated as they arise. Surgical Care : Surgery for foot deformity and scoliosis may be of benefit in selected patients. The rate of progression is variable, but more than 95% of individuals with Friedreich ataxia cannot ambulate by the time they are aged 45 years, and, on average, patients lose the ability to walk 15 years following onset of symptoms. The mean age of loss of ambulation is 25 years. Age at death is rather variable. Death usually occurs in the mid fourth decade of life. Death tends to be earlier if heart disease and diabetes are associated.

18. Vestibular disorder Vertigo is the typical symptom caused by vestibular dysfunction. most patients with vertigo have : acute vestibular failure benign paroxysmal positional vertigo Ménière's disease. Central (brain) causes of vertigo are rare by comparison, with the exception of migraine.

19. Acute vestibular failure commonly called ‘ labyrinthitis ’ or ‘ vestibular neuronitis ’, most cases are idiopathic or viral . It usually presents as isolated severe vertigo with vomiting and unsteadiness . It begins abruptly, often on waking, and many patients are initially bed-bound. The vertigo settles within a few days, though head movement may continue to provoke transient symptoms (positional vertigo) for some time. During the acute attack, nystagmus will be present for a few days. Cinnarizine, prochlorperazine or betahistine provide symptomatic relief but should not be used long term, as this may delay recovery. A small proportion of patients fail to recover fully and complain of ongoing imbalance and dysequilibrium rather than vertigo; vestibular rehabilitation by a physiotherapist may help.

20. Benign paroxysmal positional vertigo Due to the presence of otolithic debris from the saccule or utricle affecting the free flow of endolymph in the semicircular canals ( cupulolithiasis ). -transient ( seconds) vertigo precipitated by movement (typically, rolling over in bed or getting into or out of bed). Dx by Hallpike maneuver self-limiting after weeks or months. Tx Epley Maneuver

21. Ménière disease This is due to an abnormality of the endolymph that causes episodes of vertigo accompanied by tinnitus and fullness in the ear, each attack typically lasting a few hours. Over the years, patients may develop progressive deafness (typically low-tone on audiometry). Examination is typically normal in between attacks. Dx is clinical , supported by abnormal audiometry. Imaging may be indicated to exclude other focal brainstem or cerebellopontine angle pathology but will be normal in Ménière disease. Management includes a low-salt diet, vestibular sedatives for acute attacks (e.g. cinnarizine or prochlorperazine), and occasionally surgery to increase endolymphatic drainage from the vestibular system.

22. References 1- Davidson’s principles and practice of medicine. 2- CONTINUUM: Lifelong Learning in Neurology