Motor neuron diseases.pdf

motor neuron diseases ALS

1. Motor neuron
diseases

2. Motor neuron diseases.
heterogeneous●It is a progressive, group of
neurodegenerativecondition selectively affecting Upper
UMNmotor neurons ( )or Lower motor neurons (LMN) or
Both.
●There is NO involvement of sensory or other non motor
tracts.
●It causes progressive weakness and eventually death (as
a result of respiratory failure or aspiration).

3. Clinical types.
Subset of motor
neurons
involved
Clinical syndrome
●Upper motor neuron +
lower motor neuron
Amyotrophic lateral sclerosis
●Upper motor neuron Pseudobulbar palsy
Primary lateral sclerosis
Familial spastic
paraplegia
●Lower motor neuron Bulbar palsy
Spinomuscular
atrophy
Multifocal motor neuropathy
( with paraproteinemia)

5. Amyotrophic lateral sclerosis
Most commontype.●
●Also known as Lou Gehrig’s disease, after the famous
basketball player diagnosed of ALS in 1930.
●Degeneration of motor neurons (UMN and LMN) in motor
cortex, brainstem and spinal cord.
●Males > females.
●Mean age of onset - 60-65yrs.
●Average survival from onset of symptoms- 2.5 - 3.5yrs.
●90% - Sporadic.
●10%- Familial —>
copper - zinc superoxide dismutase
mutation seen in young population.

6. AMYOTROPHY.
Anterior horn cell
degeneration
Denervation of muscles
Atrophy of muscle fibers
LMNResponsible for signs.
LATERAL SCLEROSIS
Sclerosis of the anterior
and lateralcorticospinal
tract
Progressive gliosis.
UMNResponsible for
signs.

8. Etiopathogenesis.
●Protein aggregation
Pathological hallmark: ubiquitinated cytoplasmic inclusions
containing RNA processing proteins TDP43 and FUS.
●Oxidative neuronal damage
●Glutamate mediated excitotoxicity
●Mitochondrial dysfunction
●Impaired axonal transport.

9. Clinical features
●Asymmetrical, progressive weakness.
Distal upper limb muscles● are involved first.
●Initially skilled activity are affected which progresses and
gross activity also becomes difficult.
●LMN signs: wasting, fasciculations, flaccidity, loss of
tendon reflexes.
●UMN signs: spasticity, exaggerated reflexes
●Lower limb involvement may follow upper limb
involvement. Difficulty in walking with spastic gait and
pyramidal signs. Knee and ankle jerks are exaggerated.
Plantar responses

10. Muscle cramp● may be the first symptom.
●They are worse at night and ease as the disease progresses.
●Fasciculations may be frequent and multiple, localised or
generalised.
Doesn’t involve
●Sensory system
●Higher mental function
●Extraocular muscles
●Autonomic nervous system
●Bowel/Bladder
●Cerebellum.

11. Clinical patterns
1. Typical/ spinal form
●Constitutes ⅔rd of ALS cases.
●Present with simultaneous involvement of upper and lower
motor neurons, usually in one limb, spreading gradually
●Presents with focal motor weakness of distal or proximal upper
or lower limbs.
●Focal motor weakness spreads to contiguous muscle in the
same region before involvement of another region.
●Then involves other muscles and trunk muscles.

12. 2.Pseudoneurotic pattern
●Resembles neuropathy. I.e. involvement of muscles in the apparent
distribution of a peripheral nerve
●Fasciculations are present on wasted muscles.
3.Monomelic: involvement of one limb (as wasted leg syndrome,
monomelic amyotrophy, chopra’s MND).
4.Pseudopolyneuritic: weakness in both distal lower limbs.
5.Mills hemiplegic variant: weakness restricted to one half of the
body.
6.Madras MND: assoc sensineural deafness, bifacial and bulbar
weakness, bilateral optic atrophy in age <15yrs.

13. Bulbar / Pseudobulbar Palsy.
●Involves lower cranial nuclei and their supranuclear connections.
weakness of respiratory group of muscles●Presents with -
dysarthria, dysphasia, nasal regurgitation and choking.
●About 10% presents with bilateral upper limb weakness and
wasting, flail arm of flail person in barrel syndrome.
Wasting fasciculations of tongue
●Drooped head syndrome: neck extension affected.
● seen in all patients
●Cramps in the thigh, abdomen, back or tongue

14. Pseudobulba
r (UMN)
Bulbar (LMN)
Palatal reflex ++++ _ _ _ _
Pharyngeal reflexes ++++ _ _ _ _
Jaw jerk ++++ _ _ _ _
Emotional ++++ _ _ _ _
Paralysis Spastic Flaccid
Dysarthria
Tongue Small, spastic Wrinkling/
atrophic/
fasciculations.

16. Spinal/Progressive muscular atrophy.
●Presents aspure LMNdisease.
●There is flaccid weakness hypotonia, decreased tendon reflexes,
fasciculations and muscle atrophy.
●Death occurs due to respiratory muscle weakness and respiratory
failure.
Primary lateral sclerosis.
●Least common form.
●It involves upper motor neurons and presents with a slowly
progressive tetraparesis and Pseudobulbar palsy.

17. Diagnosis.
●MRI:WINE GLASS appearance
or GARLAND sign.
T2W1 showsbilateral symmetrical
hyper intensityalong corticospinal
tract (thin white arrow).

18. ●Electromyography: definitive
Long duration polyphasic action potential.
SPLIT HAND phenomenon:severe changes in the thenar eminence and
the relative sparing of hypothenar eminence.
●Myelogram: of cervical spine shows lesion in selected areas.
●Muscle or nerve biopsy.
●No biological marker identified so far.

19. Split hand phenomenon
EMG

20. Differential diagnosis of ALS

21. Treatment
●No treatment to arrest degeneration.
●Riluzole: 100mg/ day. Sodium channel blocker. Reduces
glutamate induced excitotoxicity.
●Trial drugs: IGF- 1, ceftriaxone, edaravone, tamoxifen.
●Spasticity: Baclofen, Tizanidine, memantine, Tetrazepam.
●Rehabilitation:
1.Foot drop and finger extension splint.
2.Respiratory support: tracheostomy, positive pressure ventilation,
cough assisted device.
3.Bulbar involvement: gastrostomy for speeding, speech therapy.
4.Physiotherapist, speech and occupational therapy.

22. SMA Zolgensma
●Risdiplam

23. Stephen hawking
●ALS was diagnosed in
1963
●Had the disease for
55years, the LONGEST
recorded time one had
the disease.

24. Thank you
Dr. KALAVATHI
Dept of General Medicine