Neurology: Other Less Common Conditions Flashcards
Remind yourself of the following for the cavernous sinus:
- Location
- Contents
Cavernous sinuses are paired and situated on body of sphenoid bone
Location:
- Medially: sphenoid sinus & pituitary fossa
- Laterally: temporal lobe
Contents:
- Oculomotor nerve
- Trochlear nerve
- Ophthalmic division of trigeminal
- Maxillary division of trigeminal
- Carotid artery
- Abducens nerve
State some potential causes of cavernous sinus thrombosis
Causes can be septic and aseptic:
Septic
- Sinusitis
- Facial infection
- Peri-orbital infection
- Otitis media
- Bacterial meningitis
- Sepsis
Aseptic
- Trauma
- Hypercoagulable state
- Inflammatory disease e.g. SLE
Describe possible features of cavernous sinus thrombosis
- High fever
- Headache- particularly around eyes
- Periorbital oedema
- Chemosis
- Cranial nerve palsies & associated double vision
- CNVI most common (responsible for eye abduction)
- CNIV (responsible for eye depression, abduction, internal rotation)
- Ophthalmic division of CNV (absent corneal reflex)
- Maxillary division of CNV (absent sensation cheek)
Discuss the management of cavernous sinus thrombosis
Emergency requiring admission to hospital
- IV abx
- Heparin
- May need surgery to drain if linked to infection
State some general/common features of intracranial sinus/venous thrombosis
- Headache (may be sudden onset)
- Nausea & vomiting
- Reduced consciousness
- Cranial nerve palsies
- Cavernous sinus: CNVI palsy most common
- Lateral sinus: CNVI and CNVII
- Can cause cerebral infarction hence present with symptoms & signs of stroke (will depend on region affected)
What is the investigation of choice for intracranial venous thrombosis?
MRI venography= gold standard
(CT venography is alternative & according to BMJ actually superior for early detection of cavernous sinus thrombosis. For rest MRI is superior)
State some potential causes for brain abscesses
- Recent infection in nearby site (e.g. ear, sinus)
- Trauma or surgery to scalp
- Penetrating head injury
- Embolic events from infective endocarditis
State some signs & symptoms of a brain abscess
- Signs/symptoms of raised ICP:
- Headache
- Nausea & vomiting
- Seizures
- Papilloedema
- Focal neurology
- Fever
Briefly outline management of brain abscesses
- Surgery to remove/debride abscess
- IV antibiotics
- Dexamethasone to manage increased ICP
- ?Antiepileptics for seizures
- ?Antiemetics
Remind yourself of structure of brachial plexus, include:
- Roots
- Trunks
- Divisions
*
Remind yourself what Erb’s palsy is
- Damage to upper brachial plexus (C5, C6)
- May be caused in delivery- particularly breech presentation
- Presentation:
- Waiters tip (arm adducted, elbow extended, internally rotated, supination, wrist extended)
Remind yourself what Klumpske’s palsy is
- Damage to lower brachial plexus (C8, T1)
- Usually due to forced hyperextension or hyperabduction (e.g. fall from height and grab onto something) or if baby’s arm is delivered first
- Claw hand deformity (hyperextension MCPJs, flexion of IPJs, abduction of thumb & wasting of interossei)
How does a common peroneal nerve injury present?
- Foot drop (MOST COMMON)
- Others:
- Weakness dorsiflexion
- Weakness foot eversion
- Weakness extensor hallucis longus
- Sensory loss over dorsum of foot and lower lateral leg
- Wasting anterior tibial & peroneal muscles
*Remember common peroneal splits into superficial which supplies lateral compartment of leg and deep which supplies anterior compartment of leg
Remind yourself of the sensory and motor functions of the median nerve
Motor
- Anterior of forearm
- Some intrinsic hand muscles (LOAF)
- Lumbricals 1 & 2
- Opponens pollicis
- Abductor pollicis brevis
- Flexor pollicis brevis
Sensory
- Palmar aspect of hand (including most lateral 3 and half digits)
- Distal half of most lateral three & half digits on dorsal aspect of hand
Discuss how damage to the median nerve at each of the following places would present:
- Wrist
- Elbow
- Anterior interosseous nerve (just below elbow)
Wrist
- Ape hand deformity (flattened thenar eminence, thumb adducted & internally rotated)
- Due to paralysis and wasting of intrinsic hand muscles supplied by median nerve (LOAF)
- Palmar cutaneous branch often spared as it exits proximal to the carpal tunnel
Elbow
- Paralysis of muscles in forearm & arm and sensory loss of lateral palm and lateral dorsal fingertips
- Presentation:
- “Hand of benediction” (when make a fist index & middle finger remain extended as lumbricals 1 & 2 supplied by median nerve)
- Supinated (unopposed action of supinator & biceps brachii)
- Weak flexion of wrist (can still flex slightly due to flexor carpi ulnaris)
- Weak or absent flexion of thumb (flexor pollicis longus is paralysed but deep head of flexor pollicis brevis is innervated by ulnar nerve)
- Sensory loss in median nerve distribution