Neurology Focal Weakness Flashcards
(39 cards)
what is the difference in symptoms of a stroke compared to lower motor neurone (LMN) facial weakness aka bells palsy
typically strokes cause an UMN facial weakness, and nearly always with UMN weakness of the ipsilateral arm and leg. Stroke comes on suddenly whereas bells palsy often takes a series of hours to gradually notice
UMN the forehead will be spared and the patient can move their forehead on the affected side
LMN the forehead will not be spared and the patient cannot move their forehead on the affected side
why is neuroimaging not indicated for bells palsy
it is an isolated lower motor neurone facial weakness and likely to be idiopathic
what information can you tell a patient about bells palsy
recurrence is uncommon
facial weakness can worsen over the first few days but the majority recover completely within 4-6 months
tape can be used to keep the eye closed at night
where does the facial nerve exit the brainstem and on its journey to the face what structures does it pass
cerebellopontine angle
passes the temporal bone and parotid gland
name the 5 divisions of the facial nerve
To Zanzibar By Motor Car temporal Zygomatic Buccal Marginal mandibular Cervical
what are the motor function of the facial nerve
Supplies the muscles of facial expression, the stapedius in the inner ear and the posterior digastric, stylohyoid and platysma muscles in the neck.
what are the sensory functions of the facial nerve
Sensory: carries taste from the anterior 2/3 of the tongue
what are the parasympathetic functions of the facial nerve
parasympathetic supply to the submandibular and sublingual salivary glands and the lacrimal gland (stimulating tear production).
tell me about the nerve innervation of the forehead
Each side of the forehead has upper motor neurone innervation by both sides of the brain.
Each side of the forehead only has lower motor neurone innervation from one side of the brain.
if patients present with bells palsy within 72 hours of developing symptoms nice recommending considering which medications
prednisolone either 50mg for 10 days or 60mg for 5 days followed by a 5 day reducing regime of 10mg a day
CKS don’t recommend antiviral but someone clinicians use acyclovir
as well as prednisolone what else should be prescribed for someone with bells palsy
lubricating eye drops to prevent the eye on the affected drying out
need an ophthalmology review for exposure keratopathy if develop pain in the eye
a common differential to bells palsy is Ramsay-hunt syndrome, how does this present and what is it caused by
caused by varicella zoster virus (VZV) aka herpes zoster (shingles) and presents as a unilateral lower motor neurone facial nerve palsy
patients typically have painful and tender vesicular rash in the ear canal, pinna and around the ear on the affected side. Rash can extend to the anterior 2/3 of the tongue and hard palate (treatment same as bells palsy)
name some infections that can cause LMN facial nerve palsy
Otitis media
Malignant otitis externa
HIV
Lyme’s disease
name some systemic diseases that can cause LMN facial nerve palsy
Diabetes Sarcoidosis Leukaemia Multiple sclerosis Guillain–Barré syndrome
name some traumas that can cause LMN facial nerve palsy
Direct nerve trauma
Damage during surgery
Base of skull fractures
when patient presents with facial weakness what questions do you need to ask
time of onset, any headaches or other symptoms, any changes in eye movements or vision, and changes to sensation of the face, FAST
when a patient presents with a 3 day history of weakness to the foot what questions need to be asked
Ask specially about back pain, especially any radiation to the leg, any numbness or tingling, any bladder problems
Is there any history of trauma, this could be a consequence of problems to do with the lumbar spine
Useful to know if she has been involved in any unusual activity prior to onset of these symptoms
Could this be due to a squishing of a nerve
what are the main differentials of foot weakness
lumbar nerve root lesion (radiculopathy) or common peroneal nerve palsy
what is the main difference between a lumbar nerve root lesion (radiculopathy) and common peroneal nerve palsy
A prolapsed intervertebral disc (L4/5) would almost always be associated with significant back pain & loss of the ankle reflex on the same side
A common peroneal nerve palsy is typically painless, the ankle reflex is preserved and often occurs after a period of unaccustomed activity involving prolonged kneeling
which muscles does the common perineal (fibular) nerve innervate and what are the muscles responsible for
tibialis anterior, responsible for ankle dorsiflexion, and the peroneal muscles which evert the foot (therefore can move foot up)
not tibialis posterior (tibial nerve) which is responsible for inversion
how is the foot movement different between a L5 root compression and just a common perineal nerve injury
a slipped disc would cause weakness in both the inversion and eversion of the foot as the L5 root contributes significantly to the tibialis anterior, peroneal muscle and tibialis posterior
why is the ankle reflex lost in L5 root compression
A slipped disk causing significant L5 root compression enough to cause a footdrop will almost always involve the S1 root in addition, and hence involves loss of the ankle reflex
name the 2 terminal branches of the sciatic nerve and what does the sciatic nerve innervate
tibial nerve (posterior leg and intrinsic muscles of the foot) common fibular nerve (anterior leg, lateral leg and remaining intrinsic foot muscles)
posterior thigh, entire leg and entire foot
what things should you ask about when taking a foot drop history
ask about external pressure to the knee
precipitating factors for peroneal mononeuropathy
medical history
observe a patients gait
look for swelling and erythema
look for fasciculations in the legs and arms
assess strength of the muscles
