JC21, 22 - Where is the lesion I & II Flashcards
S/S of extrapyramidal system lesion
Movement disorders:
- Miscoordination of movement
- Akinesia/ Bradykinesia
- Stiffness/ Rigidity (Lead-pipe and cogwheel)
- Tremor
- Dysphagia
- Postural Instability
S/S of cerebellar lesion (9)
Intention tremor
Dysmetria (past-pointing)
• Finger-nose test
• Heel-shin test
Dysdiadochokinesia
Dysarthria
• Slowed, slurred or scanning speech
Nystagmus
• Nystagmus on horizontal or vertical conjugate gaze
• Nystagmus towards the side of lesion
Wide-based gait
Truncal or limb ataxia
• Ataxia refers to lack of voluntary coordination of muscles
• Unable to perform tandem gait (heel-toe walking) despite normal strength
Pronator drift and rebound test
• Slow pronation of wrist and upward drift on pronator drift test
• Overshoot and bounce on rebound test
Romberg test
• Unsteadiness with eyes open
S/S of peripheral nerve lesion
Motor and sensory dysfunction
Paresthesia, numbness
LMN signs: flaccid paralysis, muscle wasting, loss of tone, loss of power, areflexia
Spinal nerve levels that form brachial and lumbosacral plexus
Brachial plexus = C5 – T1
• Anterior (ventral) rami of C5 through T1 nerve roots
Lumbosacral plexus = L1 – S4
• Anterior (ventral) rami of L1 through S4 nerve roots
• Lumbar plexus = L1 – L4
• Sacral plexus = L4 – S4
Spinal nerve levels that form the sympathetic nervous system
Sympathetic nervous system
• Emerges from thoracic and lumbar spinal cord from T1 – L2
Components of the parasympathetic nervous system
• Emerges from brainstem from CN III/ VII, IX, X (3, 7, 9, 10) (AND)
o CN III/ VII/ IX carry parasympathetic fibers to structures within H&N only
o CN X carry parasympathetic fibers to thoracic and abdominal viscera
• Emerges from sacral spinal cord from S2 – 4
o Innervate inferior abdominal viscera, pelvic viscera and arteries of erectile tissues in perineum
o e.g. Bladder emptying = S2 – 4 (Pelvic splanchnic nerve)
Define possible locations of UMN lesions and LMN lesions
UMN vs LMN lesion
- Structures involved
- Distribution
- Muscle tone
- Reflex
UMN vs LMN lesion
- Muscle wasting
- Classical signs
Frontal lobe
- Function
- Effects of damage on cognition/ behavior, physical control
- Positive phenomenon
Parietal lobe (Dominant side)
- Function
- Effects of damage on cognition/ behavior, physical control
- Positive phenomenon
(Astereognosis - cannot tell shapes/ size/ objects by touch
Agraphesthesia - Impaired ability to recognize letters or numbers drawn by an examiner’s fingertip on the patient’s skin
Agraphia - cannot write)
Parietal lobe (Non-Dominant side)
- Function
- Effects of damage on cognition/ behavior, physical control
- Positive phenomenon
Parietal lobe (Non-Dominant side)
- Function
- Effects of damage on cognition/ behavior, physical control
- Positive phenomenon
Temporal lobe
- Function
- Effect of damage on cognition and motor control
- Positive phenomenon
Occipital lobe
- Function
- Effect of damage on cognition, motor control
- Positive phenomenon
4 types of dysphasia
Receptive
Expressive
Conductive
Nominal
Describe the nature and location of 4 types of dysphasia
How to distinguish left-sided and right-sided lesions
Components of the pyramidal system
Corticospinal and corticobulbar tract
Outline the course of the corticospinal tract
Outline the course of the corticobulbar tract
Components of the basal ganglia?
Weber syndrome
- Area of infarct
- Arteries involved
- Clinical manifestation
Weber syndrome
• Site of lesion = Anterior cerebral peduncle in midbrain
• Midbrain stroke syndrome due to occlusion of paramedian branches of PCA or basilar bifurcation perforating arteries
• Characterized by ipsilateral oculomotor nerve palsy and contralateral hemiparesis
o (Ipsilateral) LMN CN III palsy
o (Contralateral) UMN CN VII palsy (Corticobulbar tract)
o (Contralateral) Hemiplegia (Corticospinal tract)
Pattern of midbrain lesion
- CN III – IV palsy
- Contralateral UMN hemiparesis (Corticospinal tract)
Parinaud syndrome
- Site of lesion
- Causes
- Clinical manifestation
Parinaud syndrome
• Site of lesion = Dorsal midbrain (tectum)
• Constellation of neuroophthalmologic findings seen with dorsal midbrain lesions including abnormalities of vertical gaze and convergence
• Caused by multiple sclerosis, pinealoma or vascular lesion
• Clinical manifestation
o Loss of vertical gaze
o Nystagmus on attempted convergence
o Pseudo-Argyll Robertson pupil (bilateral small pupils that reduce in size on a near object (i.e., they accommodate), but do not constrict when exposed to bright light (i.e., they do not react))
Outline clinical manifestation of pontine lesions
- CN V – VIII palsy
- Contralateral UMN hemiparesis (Corticospinal tract)
- Cerebellar signs (Cerebellar peduncle)
- Dysconjugate eye movements (Paramedian pontine reticular formation (PPRF))
- Internuclear ophthalmoplegia (INO) (Medial longitudinal fasciculus (MLF)
Outline clinical manifestation of medulla oblongata lesion
Medulla oblongata lesions
• CN V, IX – XII palsy
• Contralateral UMN hemiparesis (Corticospinal tract)
• Cerebellar signs (Cerebellar peduncle)
Wallenberg syndrome
- Site of lesion
- Causes
Lateral medullary syndrome (Wallenberg syndrome)
• Site of lesion = Lateral medulla
• Causes of Wallenberg syndrome
o Brainstem infarction due to occlusion of vertebral artery and its lateral medullary penetrating arteries or PICA (< 15%) (from local thrombotic occlusion, cardioembolism or arterial thromboembolism from vertebral artery dissection)
o Brainstem hemorrhage
o Brainstem demyelination (multiple sclerosis)
o Leukoencephalopathy with brainstem involvement (hypertension, drugs, autoimmune disease)
Clinical manifestations of Lateral medullary syndrome
o (Ipsilateral) LMN CN V palsy (Loss of all sensory modalities or paraesthesia of face) plus (Contralateral) Loss of pain and temperature sensation or paraesthesia in trunk and limbs (Spinothalamic tract)
o (Ipsilateral) LMN CN IX, X palsy (Dysphagia/ Dysarthria/ Hoarseness of voice due to vocal cord paralysis/ Uvula deviation/ Loss of gag reflex Aspiration pneumonia or hiccups)
o (Ipsilateral) LMN CN XI palsy
o (Ipsilateral) Cerebellar signs (Cerebellar ataxia with nystagmus towards the side of lesion) (Inferior cerebellar peduncle and cerebellar connections)
o (Ipsilateral) Horner’s syndrome (Descending sympathetic fibres injury)
o Vestibulocerebellar disturbance* (almost always present) leading to vertigo, nystagmus, vomiting and ipsilateral limb ataxia (Vestibulospinal tract)
# Define the location of conus medullaris and cauda equina Define the clinical manifestations of lesion at either location
Conus medullaris
• Termination of spinal cord with its pia mater
• Ends at the level of L1/2
• Lesion at conus medullaris = Mixed UMN and LMN lesions
Cauda equina
• Bundles of lumbar and sacral spinal nerves caudal to the termination of spinal cord
• Floats in CSF within the subarachnoid space
• Composed of lumbar, sacral and coccygeal nerve roots from L2 – C0 (10 pairs)
• Lesion at cauda equina = LMN lesion ONLY
Spinal cord lesion:
General pattern of UMN and LMN signs at spinal cord level and spinal root level
Spinal cord lesion:
General pattern of UMN and LMN signs at spinal cord level and spinal root level
Spinal cord lesion above C5
- Pattern of deficits
Spinal cord lesion between C5 and T1
Clinical manifestation
Upper limbs: LMN signs
Lower limbs: UMN signs
Respiratory distress (Lesion below C5)
o Intact diaphragmatic function
o Inhale via diaphragm and accessory muscles
o Exhale primarily through passive recoil of chest wall and lungs since primary muscles of exhalation including internal intercostal and abdominal wall muscles are paralyzed
Spinal cord lesion between T2 and T12
Pattern of deficit
T2 – T12
• Upper limbs: Spared
• Lower limbs: UMN signs
• Sphincter disturbances
o Sympathetic nervous system: Hypogastric nerve (T10 – L2)
• Erectile dysfunction
o Thoracolumbar erection centre (psychogenic erection by visual input) = T11 – L2
Spinal cord lesion between L1 and S4
Pattern of deficit
- Upper limbs: Spared
- Lower limbs: LMN signs
• Sphincter disturbances
o Sympathetic nervous system: Hypogastric nerve (T10 – L2)
o Parasympathetic nervous system: Pelvic splanchnic nerve (S2 – 4)
• Erectile dysfunction
o Thoracolumbar erection centre (psychogenic erection by visual input) = T11 – L2
o Sacral erection centre (reflex erection by tactile stimulus) = S2 – 4
Segmental/ Complete transection syndrome of spinal cord
Causes
Pattern of Sensory, Motor and Autonomic deficits
Brown sequard syndrome
Causes
Pattern of sensory, motor and autonomic deficit
Causes: Trauma e.g. knife, bullet; asymmetrical compression from tumor or spondylosis, radiation necrosis
Central cord syndrome
Cause
Pattern of sensory, motor and autonomic deficit
Clinical features depend on extent:
- At the level without extension >> bilateral spinothalamic
- Extends anteriorly >> Anterior horns deficit, LMN at the level only
- Extends laterally >> Lateral CST deficit, UMN below the level
Causes:
- Acute: spinal hemorrhage, trauma, transverse myelitis, cervical spondylosis with hyper-extension injury
- Chronic: syringomyelia, tumor
Anterior cord syndrome
Causes
Patterns of sensory, motor and autonomic deficit
Causes:
- DM, Atrial fibrillation, invasive intravascular procedures, acute hypoperfusion
Posterior cord syndrome
Causes
Pattern of sensory, motor and autonomic deficit
Conus medullaris syndrome
Cause
Pattern of sensory, motor and autonomic deficit
Cauda equina syndrome
Causes
Pattern of sensory, motor and autonomic deficit
Cauda equina syndrome
Causes
Pattern of sensory, motor and autonomic deficit
Name all tracts affected by Brown-sequard syndrome
List all tracts affected by central cord syndrome
List all tracts affected by anterior cord syndrome
List all tracts affected by posterior cord syndrome
Peripheral nerve lesion
- 2 patterns of lesion
- General neurological deficit pattern
NMJ lesion
- 2 categories
- Examples
- General deficit pattern
Neoplastic causes of spinal cord compression
