lesions physio

Question 1

Acute effects of thalamic syndrome

Answer 1

1) Acute (immediate) Mention:a) Crossed (contralateral) hemianesthesia, loss of all sensations on the opposite side of body & faceb) 2ry hyperalgesia due to release from gate inhibitory fibersc) Sensory ataxia (+Ve Romberg)

Question 2

Effects of chronic thalamic syndrome

Answer 2

a) Recovery of crude sensation onlyThe recovered sensations are:Need high threshold stimulation Poorly localizedb) 2ry hyperalgesiac) Attacks of painThalamic hyperpathia (unpleasant sensation)e) Emotional disturbancesf) Motor ataxia

Question 3

Chorea cause

Answer 3

lesion in caudate nucleus [ GABA in connections of striatum to globus pallidus externa] GPe

Question 4

Hemiballismus cause

Answer 4

Globus pallidus is inhibited. lesion in subthalamic nucleus. ( decrease glutamate)

Question 5

Athetosis cause [Mobile spasm] No Fixed position / 🐍 dance

Answer 5

lesion of Globus pallidus. ( decrease GABA)Defect in indirect pathway

Question 6

Cause of pendular jerk

Answer 6

Cerebellum lesion

Question 7

Hpotonia causes

Answer 7

LMNLAcute UMNL#Area 4 lesion* Chorea (lesion in caudate)* Neocerebellar lesion↑ Serum calcium

Question 8

Spasticity

Answer 8

D.t Chronic UMNLType :Clasp knife (initial resistance with sudden release)-velocity dependent - Hyperreflexia with no tremorsClouns is present - unilateral Circumduction gait

Question 9

Rigidity

Answer 9

D.t : ParkinsonType : -Cog-wheal (interrupted)-lead-pipe (continuous-velocity independentStatic tremors disappear by voluntary movementShuffling Bilateral gait

Question 10

Sensory ataxia

Answer 10

Site of lesion :Tabes DorsalisRomberg’s sign +VeKinetic tremors : absent only at restSpeech :NormalGait : Stamping (high)

Question 11

Motor ataxia

Answer 11

Site of lesion : cerebrocerebellumKinetic tremors is present Speech : staccato Gait : zigzag Nystagmus

Question 12

Cause Gloves & stockings: patter of sensory loss.

Answer 12

Poly-neuropathy (peripheral neuritis)

Question 13

Effects of syringomyelia

Answer 13

1- Damage of spinothalamic fibers of both sides → loss of pain & temperature on both sides at the level of the lesion → jacket distribution of sensory loss.2- Crude touch is not lost because it is partially carried by the dorsal column

Question 14

Most severe cases of syringomyelia

Answer 14

sensory effectsMotor effectsAutomatic effects Brain stem effects damage of cranial nerve nuclei (Syringobulbia)

Question 15

Tabes dorsalis effects

Answer 15

Early stage:Inflammation irritation of pain →» fibers → severe attacks of L.L pain.Late stage:→ all spinal Formation of syphilitic gumma → compression & destruction of nerves

Question 16

Argyll- Robertson pupil

Answer 16

Loss of pupillary light reflex but the pupil itself is normal & can respond to other reflexes such as the near responseIn more severe stages of tabes dorsalis Due to Damage of pretectal area (center of pupillary light reflex, in mid brain)-

Question 17

Effects of Brown Sequard Syndrome = Hemisection of the spinal cord

Answer 17

1. At the level of the lesion: On the same side of lesion: -Sensory: loss of all sensations at corresponding dermatome. Motor: lower motor neuron lesion (LMNL) = flaccid paralysis = no reflexes.2- Below the level of the lesion:-Same side:Loss of proprioception. Sensory: loss of D.C. sensationsMotor: upper motor neuron lesion (UMNL)= spastic paralysis = ↑ reflexes.Opposite side:* Sensory: loss of spinothalamic sensations.

Question 18

Cause of Stage of spinal shock

Answer 18

sudden withdrawal of the supraspinal facilitatory impulses in cortico, reticulo & vestibule spinal tracts → prim Extra↓ Excitability of spinal motor neurons & ↓Their responses to afferents.

Question 19

Effects of stage of spinal shock

Answer 19

-Loss of all reflexes- loss Autonomic Defecation & micturition reflexes (retention)- Muscle atrophy.- Bone demineralization- Vasomotor Sympathetic reflexes is lost→vasodilatation & hypotension

Question 20

Cause of recovery of reflexes

Answer 20

1) Denervation hypersensitivity of the remaining neurons →→ they can respond to afferents2) collateral from existing neurons more stimulation of motor neurons & interneurons

Question 21

Manifestations of recovery stage

Answer 21

1) Return of reflex the latest is knee and ankle jerks2) Sexual reflexes:The cortical complex sexual desire & act is lost,3) micturition Return but without voluntary control (as infants) Filling of 150 mL urine reflex evacuation of bladder (automatic bladder)4)Return of infantile reflexes:Grasp reflex +ve Babiniski5)Mass reflexFlexion of both L.L. Contraction of abdominal musclesEvacuation of bladder & rectum Increase ABPErectionSweating below level of lesion After scratching skin of L.L. or abdominal wall

Question 22

+Ve Babinski sign

Answer 22

1) Lesion in premotor area 6 ( fanning of 4 lateral toes )2) Lesion of primary motor area 4 (dorsiflexion of big toe)3) Recovery stage after spinal shock 4) UMNL

Question 23

Effects of LMNL

Answer 23

1) Ipsilateral, localized flaccid paralysis of a muscle or group of muscles supplied by the affected nerve.The paralyzed muscle may show:- Fasciculations: Felt & seenjerky contraction of a group of muscle fibersDue to pathological discharge of A.Ch from the damaged motor neuron.- Fibrillations: Felt & not seen contraction of an individual fiberDue to denervation hypersensitivity.