Neurology Flashcards
Horners syndrome signs and associated signs
Think about the pathway of the sympathetic chain
EYES: Partial ptosis and constricted pupil (reacts normally to light)
FOREHEAD: anhidrosis
CRANIAL NERVES V/IX/X: lateral medullary syndrome
HANDS: clubbing, finger abduction (lower trunk brachial plexus C8/T1 lesion)
UPPER LIMB NEUROLOGICAL EXAM: dissociated sensory loss (syringomyelia)
RESPIRATORY EXAMINATION: apical lung tumour
VOICE: hoarseness (recurrent laryngeal nerve palsy)
NECK: cervical lymphadenopathy, thyroid carcinoma, carotid aneurysm or bruit
Causes of Horners
- Brain stem lesions – vascular disease (lateral medullary syndrome), syringobulbia, tumour
- Carcinoma of the lung apex
- Neck – thyroid malignancy, trauma
- Carotid arterial lesion – carotid aneurysm or dissection, pericarotid tumour
- Retro-orbital lesions
- Syringomyelia (rare)
Signs of Lateral Medullary syndrome
Due to PICA artery
- Horner’s syndome
- Nystagmus (to the side of the lesion) (CN 8)
- Ipsilateral cranial nerve V (pain and temperature), IX and X lesions
- Ipsilateral cerebellar signs
- Contralateral pain and temperature loss over the trunk and limbs
Signs of Medial medullary syndrome
Supplied by vertebral artery and anterior spinal artery.
Medial structures
- 12th CN
- MLF - connect 3rd and 6th CN
- Medial lemniscus - continuation of posterior column tracts.
- Pyramids - continuation of the cortico-spinal tracts
Spinal Tracts
3 sensory:
- Dorsal column / Medial lemniscus - vibration + proprioception + fine touch
- Spinothalamic - pain + temp + crude touch
- Spinocerebellar - co-ordination
2 motor:
Pyramidal tracts
- Lateral corticospinal tract
- Anterior corticospinal tract
Extrapyramidal tracts -
- Rubrospinal tract
- olivospinal tract
- vestibulospinal tract
- reticulospinal tract
Differentiating bulbar and pseudobulbar palsy.
Bulbar palsy - LMN
Gag reflex – absent
Tongue – wasted, fasciculations
“wasted, wrinkled, thrown into folds and increasingly motionless”.
Palatal movement – absent.
Jaw jerk – absent or normal
Speech – nasal
“indistinct (flaccid dysarthria), lacks modulation and has a nasal twang”
Emotions – normal
Other – signs of the underlying cause, e.g. limb fasciculations.
Pseudobulbar palsy - UMN
Gag reflex – increased or normal
Tongue – spastic
“it cannot be protruded, lies on the floor of the mouth and is small and tight”.
Palatal movement – absent.
Jaw jerk – increased
Speech – spastic: “a monotonous, slurred, high-pitched, ‘Donald Duck’ dysarthria” that “sounds as if the patient is trying to squeeze out words from tight lips”.
Emotions – labile
Other – bilateral upper motor neuron (long tract) limb signs.
Types of muscular dystrophy - Signs and symptoms of each
Duchenne- X-linked recessive, dystrophin gene, unable to walk by childhood, scoliosis and intellectual disability.
Symptoms: Proximal weakness. Tip-toe gait + tightening of achilles. Protruding abdomen due to weak abdominals. Chest forward due to weak scapula muscles. Fat infiltrated bulky calves (pseudo hypertrophy). Dilated cardiomyopathy.
Becker - Same as Duchenne but milder.
Myotonic - Autosomal Dominant, Due to trinucleotide repeats, fixed sustained contraction, difficulty releasing hand grip. also have cataracts and cardiac conduction issues.
Symptoms: Narrow face, baldness, cataracts, no chin.
Facioscapulohumeral - Autosomal dominant DUX4 gene. affects face, scapula and humeral muscles first. Commonly have winged scapula, hearing loss and foot drop. Asymmetric severity. Can cause blindness.
Signs of CN3 palsy
CLINICAL FEATURES
● Complete ptosis (partial ptosis may occur with an incomplete lesion)
● Divergent strabismus (eye ‘down and out’): limited adduction and elevation
● Dilated pupil unreactive to direct or consensual light and unreactive to accommodation
Method to test if CN4 palsy co-exists with CN3 palsy
o Tilting the patient’s head to the same side as the lesion. The affected eye will intort if the lesion is intact
o Asking the patient to look down and across to the opposite side from the lesion and look for intortion
Causes of a CN3 palsy
● Central o Vascular (e.g. brain stem infarction) o Tumour o Demyelination o Trauma ● Peripheral o Compressive lesions: ▪ Aneurysm (usually on the posterior communicating artery) ▪ Tumour causing raised intracranial pressure ▪ Nasopharyngeal carcinoma ▪ Orbital lesions ▪ Basal meningitis o Infarction: diabetes mellitus, arteritis (pupil is usually spared) o Trauma o Cavernous sinus lesions
Causes of CN6 palsy
● Bilateral o Trauma o Wernicke’s encephalopathy o Raised intracranial pressure o Mononeuritis multiplex ● Unilateral o Central: ▪ Vascular ▪ Tumour ▪ Wernicke’s encephalopathy ▪ Multiple sclerosis o Peripheral ▪ Diabetes, other vascular lesions ▪ Trauma ▪ Idiopathic ▪ Raised intracranial pressure
Causes of Nystagmus
● Horizontal:
o Vestibular lesion – chronic lesions cause nystagmus to the side of the lesion
o Cerebellar lesion – unilateral disease causes nystagmus to the side of the lesion
o Internuclear ophthalmoplegia – nystagmus is in the abducting eye, with failure of adduction on the AFFECTED SIDE. This is the result of a medial longitudinal fasciculus lesion. The most common cause in young adults with bilateral involvement is multiple sclerosis; in the elderly consider brainstem infarction
● Vertical:
o Brain stem lesion:
▪ Upbeat nystagmus suggests a lesion in the floor of the fourth ventricle
▪ Downbeat nystagmus suggests a foramen magnum lesion
o Toxic – phenytoin, alcohol (may also cause horizontal nystagmus)
Signs of Progressive supranuclear palsy
- loss of balance, lunging forward when mobilizing, fast walking, bumping into objects or people, and falls.
- vertical gaze palsy with intact occulocephalic reflex.
Causes of a 5th nerve palsy
● Central (pons, medulla and upper cervical cord) o Vascular o Tumour o Syringobulbia o Multiple sclerosis ● Peripheral (posterior fossa) o Aneurysm o Tumour (skull base, e.g. acoustic neuroma) o Chronic meningitis ● Trigeminal ganglion (petrous temporal bone) o Meningioma o Fracture of the middle fossa ● Cavernous sinus (associated third, fourth and sixth nerve palsies) o Aneurysm o Thrombosis o Tumour ● Other o Sjogren’s syndrome o SLE o Toxins o Idiopathic
Causes of cavernous sinus syndrome
- Tumor- Meningioma, chordoma, neuroma, pituitary adenoma, metastases, lymphoma, nasopharyngeal carcinoma, chondrosarcoma, hemangioma, neuroblastoma
- Inflammatory Disease - Tolosa-Hunt syndrome, sarcoidosis
- Trauma- Basal skull fracture, operative trauma to cavernous sinus after skull base surgery
- Vascular - Intracavernous aneurysm, carotid-cavernous fistula, cavernous sinus thrombosis
- Infection - Mucormycosis, aspergillosis, actinomycosis, nocardiosis, mycobacterium, herpes zoster.
Causes of a 7th nerve palsy
● Upper motor neurone lesion (supranuclear) o Vascular o Tumour ● Lower motor neurone lesion o Pontine (often associated with nerves V, VI): ▪ Vascular, tumour, syringobulbia, multiple sclerosis o Posterior fossa ▪ Acoustic neuroma ▪ Meningioma o Petrous temporal bone ▪ Bell’s Palsy ▪ Ramsay Hunt Syndrome ▪ Otitis media ▪ Fracture o Parotid: ▪ Tumour ▪ Sarcoid
Causes of bilateral LMN facial weakness
● Guillain-Barre syndrome
● Bilateral parotid disease (e.g. sarcoidosis)
● Mononeuritis multiplex (rare)
Causes of cranial nerve palsies
● Central
- Vascular
- Tumour
- Syringobulbia
- Motor neurone disease
- Multiple Sclerosis
● Peripheral (posterior fossa)
- Aneurysm
- Tumour
- Infections
- polio
- Chronic meningitis
- Guillain-Barre syndrome
- Trauma/fracture of facial bones/ base of skull
- Infiltrative - sarcoid/amyloid
- Arnold-Chiari malformation
8th nerve testing interpretation
RINNE’S TEST: 256-hertz tuning fork placed on the mastoid process, behind the ear, and when the sound no longer heard, placed in line with the external meatus
● Normal – the note is audible at the external meatus
● Sensorineural deafness – the note is audible at the external meatus (air and bone conduction reduced equally)
● Conduction (middle ear) deafness – no note is audible at the external meatus – negative result
WEBER’S TEST: 256-hertz tuning fork placed on the centre of the forehead
● Normal – sound is heard in the centre of the forehead
● Sensorineural deafness – sound is transmitted to the normal ear
● Conduction deafness – sound is heard louder in the abnormal ear
- Conductive hearing loss occurs when sound conduction is impeded through the external ear, the middle ear, or both.
- Sensorineural hearing loss occurs when there is a problem within the cochlea or the neural pathway to the auditory cortex.
Multiple cranial nerve palsies
- Nasopharyngeal carcinoma
- Chronic meningitis (carcinoma, tuberculosis, sarcoidosis)
- Guillain-Barre syndrome, including Miller-Fisher variant
- Brain stem lesions
- Arnold-Chiari malformation
- Trauma
- Lesion of the base of the skull
- Mononeuritis multiplex (e.g. diabetes mellitus)
- Leptomeningeal disease
- Cavernous sinus syndrome - 3,4,V1,V2.
Types of Aphasia and sites
RECEPTIVE APHASIA
- Wernicke’s area – temporal gyrus in dominant lobe
EXPRESSIVE APHASIA
- Broca’s area – frontal gyrus
CONDUCTIVE APHASIA
- Arcuate fasciculus (temporal lobe)
NOMINAL APHASIA (difficulty naming objects)
- Angular gyrus (temporal lobe) – small localised lesion
- Encephalopathy (metabolic, toxic), pressure effects from distant space-occupying lesion
- Recovery phase from any dysphasia
Types of Dysarthria (not dysphasia)
o Cerebellar speech: slurring or “scanning” (i.e. irregular and staccato)
o Pseudobulbar palsy: slow, hesitant, hollow-sounding speech with a harsh, strained voice
o Bulbar palsy: nasal speech with imprecise articulation
Causes for drift
● Upper motor neurone weakness (usually downwards owing to muscle weakness)
● Cerebellar lesion (usually upwards owing to hypotonia)
● Posterior column loss (any direction owing to joint position sense loss)
Upper limb myotomes
● Shoulder abduction: C5,6 ● Shoulder adduction C6, C7, C8 ● Elbow flexion: C5, C6 ● Elbow extension: C7, C8 ● Wrist flexion: C6, C7 ● Wrist extension C7, C8 ● Fingers extension: C7, C8 ● Finger flexion C7, C8 ● Finger abduction: C8, T1