ELFH: neurology 1 Flashcards
syncope?
temporary loss of consciousness due to reduction in blood flow. Usually preceded by dizziness. Fear (reflex) cough, micturition (reducing venous return)
arrhythmia cause dizziness and fainting?
reduced cardiac output thus reduced cerebral blood supply
postural hypotension causes dizziness an fainting?
on rising from lying or sitting, in elderly or associated with Addison’s
causes of dizziness and fainting?
syncope
arrhythmias
postural hypotension
epilepsy
hypoglycaemia
panic attacks
transient ischaemic attacks
UMN lesion?
opposite side and lower half of face (can wrinkle forehead)
Weakness of the lower part of face only as the frontal muscles have a bi-cortical representation
Effect would be on the contralateral side
Patient would retain blinking and forehead wrinkling
Common in strokes
LMN lesion?
same side and full side
facial nerve - bell’s palsy
causes of LMN lesion?
- Disease of the anterior horn cells
- Lesions at the spinal or cranial nerve root, e.g. disc lesions, tumours
- Peripheral nerve lesions, e.g. compression, trauma and poly-neuropathy
- There may also me issues at the motor end plate, e.g. myasthenia gravis
All muscles of expression affected
On the ipsilateral side
No blinking and forehead wrinkling
Causes are cerebro-pontine angle tumour, petrous bone lesions/infections, parotid gland pathology (which may be iatrogenic), skull base lesions
Commonest is Bells Palsy
path of sensory nerves to the brain?
carry info from the periphery into the brain
arrive at the back (dorsum) of the spinal cord or via the sensory based cranial nerves
to thalamus
sent to areas important in actioning the infomation e.g. cerebellum
What symptoms would indicate sensory disturbance?
The main indicators of sensory nerve problems are:
Pins and needles (parasthesia)
Numbness (anaesthesia)
Pain
peripheral nerve lesion vs central tract nerve lesion?
peripheral nerve damage will affect the distribution of that nerve e.g. ID
CENTRAL TRACTS: affect whole limb or area
loss of pain and sensation on opposite side implies what?
Loss of pain and sensation on opposite sides implies a spinal cord lesion
loss of pain and sensation on same side suggests the lesion is from where?
lesion in pons
lesion in the cortex vs thalamic region?
cortex = sensory loss on one side usually with no pain
Thalamus = pain
lesion in the pyramidal and cerebellum?
uncoordinated and weak movements
what may affect the cerebellum?
Multiple sclerosis
Tumours
Alcohol abuse
Anticonvulsant drugs
Cerebellar lesions will result in the following signs/symptoms which should be noticed by the clinical care providers:
Tremor
Clumsiness
Nystagmus
Dysarthria (difficulty speaking)
Tremor of the head (titubation)
what nerves nuclei are found i the midbrain?
iii - oculomotor
iv - trochlear
what nerves nuclei are found in the pons?
v
vi
vii
viii
what nerves nuclei are found in the medulla?
ix
x
xi
xii
loss of function of CNI called?
loss of smell = anosmia
tests for the optic nerve?
Visual acuity (with a Snellen chart)
Visual field (with confrontation technique)
Fundoscopy
what nerve constricts the pupil?
oculomotor - parasympathetic
Why does the pupil dilate? pathway
the sympathetic efferents which have arrived via the carotid vascular system will pass through the ciliary ganglion to finish at the pupillary muscle target and cause it to dilate.
what may cause pupils to permanently dilate?
- III nerve palsy
- Anticholinergic drug
- Holmes Adie pupil, absent light reflex found in young women , little significance and may indicate generally slow reflexes
What may cause pupils to be permanently constricted?
- Cholinergic drugs
- Horner’s syndrome, interruption of sympathetic efferents at root of neck by metastatic disease such as lung cancer (Pancoast tumour) or trauma in the neck
- Argyll Robinson pupil, associated with syphilis or even diabetes
- Opiates
eye nerves?
iii - oculomotor
iv - trochlear
vi - abducens
what could affect nerves III, IV, VI?
Infarction
Tumours
Multiple sclerosis
Motor neurone disease
Trauma
What is the role of the oculomotor nerve?
constrict pupil
levator palpebrae superioris
all other extra-ocular muscles
lesions in oculomotor result in?
eye down and out and fixed dilated pupil.
Subarachnoid bleed from a Berry aneurysm is also a common cause. You should also consider diabetes.
what is the role of trchlear nerve?
superior oblique muscle
eye down and medially
what happens when trochlear nerve is damaged?
double vision when looking down
what does the abducens nerve cause?
lateral rectus - lateral movement
what occurs if abducens nerve damaged?
Eye turns medially in lesion due to unopposed medial rectus activity, leading to double vision.
what does trigeminal nerve supply?
Through its three divisions this nerve supplies sensation to the face and scalp back to the vertex.
It provides sensory information from mucous membranes of sinuses, nose, oral cavity and the teeth.
In addition it has a motor root which supplies, via the mandibular division, the muscles of mastication.
A, B, C, by what nerve?
mandibular nerve of V supplies motor innervation to what?
muscles of mastication
How to test trigeminal nerve?
- Sensory loss to the face, possibly limited to one of the territories dependent upon the site of the lesion. This can be tested with cotton wool and patient specific pins
- Loss of corneal reflex
- Intra-oral sensory loss
- Jaw will deviate to side of the lesion and temporalis and masseter can be palpated to assess their function during clenching
describe trigeminal neuralgia?
sudden, short-lived, electric-like recurrent pain found in the distribution of one of the trigeminal nerve divisions.
who is likely to get trigeminal neuralgia?
It mostly occurs in the elderly but if it occurs in younger patients the clinician must consider multiple sclerosis.
It may have a trigger spot or be related to a repeated function such as talking or washing the face or eating.
tx for trigeminal neuralgia?
Carbamazepine or oxcarbazine are the two main drug treatments. Other drugs with some benefit include lamotrigine, phenytoin and gabapentin.
If drugs fail then an increasing number of patients undergo some form of surgery. This may be peripheral nerve destruction with laser, cryotherapy or glycerol injection.
Central ganglion thermocoagulation or percutaneous balloon compression.
Some patients may opt for vascular decompression of the ganglion which produces very good long term results, but not without risks.
what can you mistake trigeminal neuralgia for?
dental pain
other causes of LMN lesion?
- Parotid tumour
- Parotid surgery
- Local anaethesia infiltrating into the parotid gland after giving an inferior dental block. This is normally a transient phenomenon
- Sarcoidosis
- Tumours of the skull base
- Lesions in the pons, e.g. demyelination or infarction
- Melkersson Rosenthal syndrome; (facial nerve palsy, swelling of the face and fissured tongue
- Ramsay Hunt Syndrome; Herpes Zoster infection of VII ganglion (geniculate) leaves facial palsy and vesicular ulcers on the palate and ear
clinical features of bell’s palsy?
- Ear pain preceding the event
- Stiffness and difficulty moving any muscles on the affected side including difficulty in blinking
- Altered taste and hyperacusis (sensitive to sounds) on the same side
- Reduced tears on ipsilateral side (greater petrosal nerve via the pterygopalatine ganglion)
management of bells palsy?
- Most cases recover although some may have some re-innervation issues e.g. tears and saliva produced when eating (crocodile tears)
- Treatment includes high dose steroids and a short course of aciclovir, lubrication for the eye and eye protection
- Recovery may take eight weeks although 10-20% may not fully recover
symptoms of cochlear nerve damage?
deafness and tinnitus.
The majority of causes of cochlear nerve or cochlear damage are:
Tumours (cerebellopontine angle)
Petrous bone disease
Ménière’s disease
Drugs (gentamicin)
Old age
Problems with the vestibular portion lead to:
- Vertigo, the illusion of movement
- Manifest to the outside world as nystagmus, an oscillation of the eyes
what nerves are usually affected together?
Glossopharyngeal IX, vagus X, accessory XI and hypoglossal nerves XII originate in the medulla
lesions of nerves IX-XII result in what?
bulbar palsy which is commonly a LMN lesion and manifests as:
- Dysarthria
- Dysphagia (choking)
- Wasted and fasciculating tongue. This can also be a lesion above the nuclei (UMN), i.e. a stroke, MND or even MS, will lead to a pseudobulbar palsy in which the tongue will not be wasted or fasciculating.
Each of the nerves can be damaged outside the skull and result in individual signs and symptoms.
