Movement disorder

 

THE EXTRAPYRAMIDAL SYSTEM

DEFINITION:  The extrapyramidal system is a neural network that is part of the motor system that causes involuntary reflexes and movement, and modulation of movement (i.e. coordination).

STRUCTURE:

  Centers: the corpus striatum, the substantia nigra, thalamic and subthalamic nuclei

  Inter connections: the above centers are interconnected with: The cerebral cortex, the cerebellum, the reticular formation, the cranial nerve nuclei (particularly the vestibular nerve) and the spinal cord

 

 

 Functions of the extrapyramidal system

 

  Regulation of voluntary motor activity

  Control of the muscle tone

  Maintenance of emotional and associative movements

 

Disturbance of extrapyramidal functions

 

It is now clear that in many extrapyramidal disorders there are specific changes in neurotransmitter profile rather than discrete anatomical lesions

 

 1. Disturbance in the control of voluntary motor activity resulting in involuntary movements which may be of two main types:

  Rhythmic and regular as in parkinsonism

  Dysrhythmia and irregular as in chorea, athetosis and dystonia

 

2. Disturbance in the normal muscle tone resulting in hypertonia (rigidity)

 

3. Disturbance in the maintenance of emotional and associated movements resulting in bradykinesia (mask face, infrequent blinking and loss of swinging during walking)

Extrapyramidal disorders are classified broadly on clinical grounds into:

 

  1. The akinetic-rigid syndromes in which poverty of movements predominates
  2. The dyskinesias in which there are a variety of excessive involuntary movements

  

Movement disorders

 

Akinetic-rigid syndromes

 

Dyskinesias

 

 

Ø  Idiopathic Parkinson's disease

 

Ø  Paroxysmal dyskinesias

Ø  Drug-induced parkinsonism

(e.g. phenothiazines)

 

Ø  Essential tremor

Ø  MPTP-induced parkinsonism [methylphenyltetrahydropyridine]

 

Ø  Chorea

Ø  Postencephalitic parkinsonism

 

Ø  Hemiballismus

Ø  Parkinsonism-plus

 

Ø  Myoclonus

Ø  Childhood akinetic-rigid syndrome

Ø  Torsion dystonia’s

 

 

Ø  Tic or 'habit spasms'

 

 

 

 

PARKINSONISM

 

  Parkinsonism (shaking palsy) is a condition in which there are static regular tremors, hypertonia of the muscles of the body with bradykinesia

CAUSES


1- IDIOPATHIC PARKINSON’S DISEASE

  The cause is unknown. There is degeneration of the pigmented cells of the substantia nigra, and basal ganglia neurons.

  It affects both sexes and occurs usually above the age of fifty years

  The onset is usually gradual with slowly progressive course

  Static tremors are more manifest than rigidity

  

2- POST ENCEPHALITIC

  Occurs with acute onset, regressive or stationary course at any age

  May be associated with other clinical manifestations:

q  Oculogyric crisis: spasm of conjugate eye movements mainly upwards

q  Greasy face

q  Sialorrhoea

q  Diabetes insipidus

q  Pyramidal signs

  Static tremors and rigidity are equally manifest

3.    CEREBRO-VASCULAR ATHEROSCLEROSIS

 

  The age of onset is usually above the age of sixty years

  The onset is gradual with remissions and exacerbations

  Rigidity is more manifest than static tremors

  May be associated with hypertension, diabetes mellitus and coronary heart disease

 

4- DRUG-INDUCED

  Reserpine

  Phenothiazines

5- NEOPLASTIC

  tumors of the basal ganglia

6- TRAUMATIC

Repeated trauma to the head as in boxer

 

  CLINICAL PICTURE

1- Static tremors

  Rhythmic occurring at a rate of 4-8 / second

  May start in one hand and spread to other parts of the body

  Characteristically pill-rolling movements between the thumb and the forefinger are seen

  Tremors increase with emotional, anxiety and fatigue and disappear during sleep and during active voluntary movements

2- Rigidity of the muscles

  More proximal than distal

  Flexors are affected more than extensor

  On clinical examination the resistance may be continuous throughout the act to the same degree (lead pipe rigidity) or interrupted by the tremors (cog wheel rigidity)

  Stiffness of the limbs develops causing difficulty in starting movements and walking (slow, shuffling gait)

3- Akinesia:

 Loss of emotional and associative movements resulting in:

  Immobile face with infrequent blinking (mask face)

  Monotonous speech

  Loss of swinging of the arms during walking

 

STRATEGY OF TREATMENT

 

(1)ñ Dopamine

Carbidopa/l-dopa

Dopamine agonists:        

Ø  Apomorphine,                                                                      

Ø  Cabergoline

Ø  Ropinirole,                                                               

Ø  Pramipexole

Ø   

COMT inhibitors: Entacapone

MAO Inhibitors: e.g. Selegiline (B-type)

Inhibitors of dopamine re-uptake: Amantadine

(2) ò Acetylcholine

     Anticholinergic

     Antihistaminics

(3) Other Neurotransmitters

(4) Surgery: Thalamotomy  - Pallidotomy

  Transplantation of dopamine-containing adrenal medulla (fetal or autologus)

CHOREA

DEFINITION:

  Involuntary static dysrhythmic jerky pseudo purposive movements of the face, trunk and/or limbs

TYPES

  Rheumatic chorea (Sydenhan’s Chorea)

  Huntington’s chorea

RHEUMATIC CHOREA
(
Sydenhan’s Chorea)

  This is a post infective chorea occuring largely in children and young adults

  Although rheumatic heart disease is sometimes found, the patient usually does not have a fever or other features of rheumatic fever. The antistreptolysin-O titer and ESR are sometimes normal.

  It may recur, or appear in adult life during pregnancy as chorea gravidarum or in those taking hormonal contraceptives

Clinical picture:

  Choreic movements: the movements increase with emotional stress and disappear during sleep

  Hypotonia

  Emotional instability

Treatment:

  Patients may require sedation but recovery occurs spontaneously within weeks or months

  Acetyl salicylic acid

  Haloperidol 3mg 2-3 times daily

  Corticosteroids in cases of rheumatic activity

HUNTINGTON’S CHOREA

  A heridofamilial type of chorea inherited as autosomal dominant . The children of an affected parent have a 50% chance of inheriting the disease

  The onset is gradual with a progressive course occuring in middle age

  The choreic movements are usually gross interfering with feeding and walking

  Associated with marked mentality changes progressing to dementia

Treatment:

  1. Relatives of patients should perform genetic counseling to detect any carrier state
  2. Phenothiazines or haloperidol to control the involuntary movements

HEMIBALLISMUS

 

  Acute onset of severe violent swinging movements of one side of the body

  Due to a lesion mostly vascular (infarction or hemorrhage) in the subthalamus

  Treated by phenothiazines or haloperidol to control the movements

ATHETOSIS

  Involuntary, irregular static, snake like movements affecting the extremities

  They are associated with hypertonia

  May occur due to hypoxic neonatal brain damage or post encephalitic

  Anticholinergic drugs may be helpful

DYSTONIA

 

  Involuntary, irregular static, very slow, torsion or twisting movements involving the neck, trunk or proximal muscles of the extremities

  Associated with hypertonia during the movement

TYPES

1. Generalized: a familial disorder starting in childhood

2. Focal:

  Spasmodic torticollis

  Oromandibular dystonia

  Writer’s cramp: there is dystonia of the muscles of the hand on attempting to write

HEPATOLENTICULAR DEGENERATION
(Wilson’s disease)

  Autosomal recessive disorder of copper metabolism leading to deposition of copper in the basal ganglia causing extrapyramidal manifestations in the form of choreo-athetosis, dystonia, tremors and bradykinesia

  Deposition of copper in the cornea produces Kayser-Fleicher ring

DR. PUNEET AGARWAL
M.D, D.M(Neurology), FCCN(UCLA,USA)
Ex Asst. Prof Neurology, AIIMS, N.Delhi
HEAD OF NEUROLOGY

Max Superspeciality Hospital
Saket, N.Delhi
Ph: 011-66116666(O), 9971545666(m),