2the main cause behind the movement disorders is dysfunction of deep seated sub cortical gray matter called basal ganglia with subsequent affection of their NT (dopamine and Ach) .,although there is no universally accepted definition of BG ,BUT for clinical purposes it consisting of caudate ,putamen, globus pallidus .subthalamus and substantial nigra.Basic circuit loops in BG:CORTICO-STRIATO-CORTICALNIGROSTRIATALSTRIATOPALLIDAL
3TremorInvoluntary rhythmic oscillation involving flexion and extension around a joint classified best in relation to motor activity in to:RESTING=static T. : in rest state typically seen Parkinson dis. =pen rolling T. . the rate of t is 4-6hz(slow) ,other causes of resting one is Wilson’s disease , and heavy metal poisoning (mercury).ACTION T . is of 2 types : postural and intention T.POSTURAL T. :-PSL. Tremor:-------Enhanced PSL tremor:-------cerebellar disease------Wilson’s disease------Benign essential tremor: autosmal D. , or idiopathic ,50 % positive family history ,it can affect head and neckINTENTION TREMOR : seen in cerebellar disease ,Wilson’s disease, drug toxicity alcohol, anticonvulsants, sedatives).Asterixis ? episodic loss in postural tone and M. activity causes sudden flexion of the wrist followed return back to extension ,more properly considered as type of myoclonus than tremor seen in patient with metabolic encephalopathy. it may associated with Post. tremor. How detect it?
5Choreawhich is rapid irregular muscle jerk that is purposeless ,and forceful occur involuntarily in different parts of the body.It may be mild in form of persistent restlessness and clumsiness to sever one interfering with daily activity in form of sever invol. and forceful movement with facial grimacing and tongue movement with gait affection.Pathology? Is unclear ,in some it associated with atrophy (cell loss) of caudate and putamen.Causes:Hereditary: as in Huntington’s chorea, benign hereditary chorea, Wilson’s disease , familial chorea with acanthocytosis.Static encephalopathy: cerebral palsy ,Sydenham’s choreaChorea gravidarumDrug toxicity as dopamine agonist as levodopa and antipsychotic, phenytoin ,lithium , and oral contraceptives.Medical disorders : thyrotoxicosis ,hypoparathyroidism ,or Addison’s disease ,Hypocalcemia , hypomagnesaemia, polycythemia ,hypernatremia ,SLE ,hepatic cirrhosis ,encephalitisCVA:Str. pathology of Subthalamic n.
6Dystonia and Athetosis? Hemiballismus?Unilateral chorea violent as proximal M. is involved. it is due to contralateral subthalamic nucleus mainly as vascular accident or following thalamotomy.Dystonia and Athetosis?Athetosis? Is slow distal ,irregular ,sinusoidal in character (piano playing) ,when it sustained leading to abnormal posture we call it dystonia ,which can be generalized or localized in one or 2 limbs segmental) .if it affect group of muscle called focal dystonia as writers cram or torticollis.Nearly all EP involuntary movement are disappear in sleep.Etiology?Cerebral palsyWilson’s diseaseHuntington’s CDrugsEncephalitisIschemic anoxiaIdiopathic: hereditary or sporadicIdiopathic torsion dystonia.Progressive supranuclear palsy.
7Myoclonus?Sudden rapid twitching like M. contraction. it can be spontaneous or action (on initiation of movement), it can be essential myoclonus or epileptic myoclonus ,it can be segmental or generalized ,it can be PSL or symptomatic?Generalized M. CAUSES?PSL :nocturnal and hiccupEssential DD M. EpilepsyEpilepticSymptomatic: degenerative? , infection? , metabolic?Differentiation between epileptic versus non E. myoclonus is impossible some times .it can be by EEG.Segmental M.:can arise from lesion affecting CC, brainstem ,or spinal Cpalatal m.(dentato -rubro-olivary pathways in stroke or MS )associated with audible click with synchronous movement of ocular ,facial or bulbar muscle.Epilepsia partialis continuaSame causes that produce symptomatic G. myoclonus. ex: non-k. Hyperosmlar hyperglycemia.