lesion II Flashcards Preview

neuro Anatomy 3 > lesion II > Flashcards

Flashcards in lesion II Deck (16):
1

What cranial nerves and tracts are closely located to midline of pons

- TRACTS

--> pyramidal tract

--> medial lemniscus

CRANIAL NERVES (level of lesion is localized by CN)

--> OCULOMOTOR (CNIII) = UPPER alternating hemiplegia

--> ABDUCENT (CN VI) = MIDDLE alternating hemiplegia

--> HYPOGLOSSAL (CN XII) = LOWER alternating hemiplegia

2

define alternating hemiplegia

- includes syndrome in which

--> CRANIAL NERVE MOTOR deficits are exhibited on ONE SIDE

WHEREAS

--> DESCENDING LONG MOTOR TRACT deficits are exhibited on the OPPOSITE SIDE

3

What tracts are located laterally

- Spinothalamic tract

- spinal tract of V

4

What cranial nerves located laterally

- Trigeminal (CN V) = midpons

- Facial (CN VII) = caudal pons

- Vestibulocochlear (CN VIII) = caudal pons, medulla

- Glossopharyngeal (CN IX) = medulla

- Vagus (CN X) = medulla

*Horner's syndrome = IPSILATERAL TO LESION

*CEREBELLAR SIGNS = ATAXIA, ipsilateral to lesion

5

Describe Dysarthria hemiparesis (pure motor hemiparesis) syndrome

- CAUSED BY Basilar artery (PARAMEDIAN BRANCHES)

- Structures affected:

--> CORTICONUCLEAR tract (UMN) = CONTRALATERAL lower face weakness and DYSARTHRIA

--> CORTICOSPINAL tract (UMN) = deficits in CONTRALATERAL upper and lower limb weakness

6

Define Dysarthria

- Motor speech disorder due to weakness/paralysis of the mouth (lips, tongue and lower face)

7

Describe ataxic Hemiparesis Syndrome

- Caused by occlusion in PARAMEDIAN BRANCHES (ventral territory of the pons)

--> CORTICONUCLEAR tracts (UMN) = CONTRALTERAL lower face weakness and DYSARTHRIA

--> CORTICOSPINAL tract (UMN) = CONTRALATERAL upper and lower limb weakness (motor hemiparesis)

--> PONTINE NUCLEI/PONTOCEREBELLAR FIBERS = CONTRALATERAL ATAXIA

8

Describe FOVILLE'S SYNDROME

- Occluded PARAMEDIAN BRANCHES (ventral and dorsal territories of pons)

- CORTICONUCLEAR tract = CONTRALATERAL lower face weakness and DYSARTHRIA

- CORTICOSPINAL tract = CONTRALATERAL upper and lower weakness

- FACIAL COLLICULUS (LMN)

--> abducen nucleus/paramedian pontine reticular formation (PPRF) = ipsilateral horizontal (lateral) gaze paralysis

--> facial nerve root fascicles = IPSILATERAL face paralysis

9

Pontine Wrong-way Eyes syndrome

- Caused by OCCLUDED Paramedian branches (supply ventral and dorsal territories of pons

- STRUCTURES AFFECTED

--> Corticonuclear tract = Dysarthria and CONTRALATERAL lower face weakness

--> corticospinal tract = CONTRALATERAL upper and lower limb weakness

- Abducens nucleus or Paramedian pontine reticular formation (PPRF) = IPSILATERAL lateral gaze paralysis

10

Millard-Gubler syndrome

- Caused by Paramedian branch occlusion

- STRUCTURE

--> corticonuclear tract = CONTRALATERAL lower face weakness and dysarthria

--> Corticospinal tract = CONTRALATERAL upper and lower limb weakness

--> Facial nerve fascicles (LMN) = IPSILATERAL facial weakness

11

What regions are variably invovled in Lesion in Medial Pontine basis and tegmentum

- Caused by occlusion of paramedian branches

- STRUCTURES
--> Medial lemniscus = CONTRALATERAL decreased proprioception, vibratory sense and tactile discrimination

--> Medial longitudinal fasciculus (MLF) = internuclear ophthalmoplegia (INO)

12

describe the lesion of the lateral caudal pons (AICA syndrome)

- caused by AICA occluded

--> Middle cerebellar peduncle = IPSILATERAL ataxia

--> Vestibular nuclei = vertigo and nystagmus

--> Trigeminal nucleus/tract = IPSILATERAL facial decreased pain and thermal sense

--> spinothalamic tract = CONTRALATERAL body decreased pain and thermal sense

--> Descending sympathetic fibers = IPSILATERAL horner's syndrome

13

describe lesion in DORSOLATERAL rostral pons (superior cerebellar artery syndrome)

- Caused by occlusion in superior cerebellar artery

- SUPERIOR cerebellar peduncle and cerebellum = IPSILATERAL ataxia and cerebellar origin

14

Medial medullary syndrome

- Lesion in medial medulla caused by occlusions of anterior spinal artery (paramedian branches) or vertebral artery (paramedian branches)

- structures affected (infarction)

--> corticospinal tract = weakness in CONTRALATERAL upper and lower limbs (contralateral hemiparesis)

--> hypoglossal nerve and nucleus (LMN) = weakness/paralysis of the IPSILATERAL tongue and ATROPHY of the IPSILATERAL tongue muscles

--> Medial lemniscus = CONTRALATERAL decreased vibratory and proprioceptive sensation and discriminatory (fine) touch sensation

15

Describe the cause Lateral medullary syndrome (WALLENBERG syndrome)

- Lesion in Lateral medulla

- Caused by vertebral artery (thombosis) or PICA (thrombosis)

16

What structuers are affected in Wallenberg's syndrome (lateral medullary syndrome)

- Inferior cerebellar peduncle = Ipsialteral ataxia

- vestibular nuclei = unsteady gait, vertigo, nausea, vomiting

- spinothalamic tract = decrease/loss of pain and thermal sense from CONTRALATERAL side

- spinal tract/nucleus of V = decrease/loss of pain and thermal sense from IPSILATERAL face

- Descending sympathetic fibers = ISPILATERAL Horner's syndrome

- nucleus ambiguus = dysphonia, dysphagia, ispilateral decrease of gag reflex

- nucleus solitarius = decrease in taste sensation IPSILATERAL tongue

- Loss of vertical orientation = perceives world as it is upside down or turned sideways