Download CM 4- Cranial Neuropathies Trigeminal Neuralgia Clinical

CM 4- Cranial Neuropathies
Trigeminal Neuralgia
• Clinical presentation
– Brief unilateral paroxysms of electric-like pain in the distribution of one or more
divisions of the trigeminal nerve
– A deep, dull ache is often present between attacks
– Triggers often include
• Brushing teeth
• Chewing
• Talking
• Cold wind on the face
– Periodic remissions are common
• Can last up to 6 months
– Permanent spontaneous remissions are very rare
• Mechanism
– Focal demyelination of the trigeminal nerve
• May be due to vascular compression
– May be due to intracranial lesion causing nerve irritation
– May be due to central cause such as multiple sclerosis in younger patients
• Evaluation
– Diagnosis usually made clinically
– Exclude structural/demyelinating lesions
• MRI of the brain without and with contrast as well as intracranial MRA of the
brain
• Treatment
– Medications: #1 treatment
• carbamazepine
• oxcarbazepine
• phenytoin
• valproic acid
• gabapentin
• pregabalin
• baclofen
• Analgesics for breakthrough pain
– Surgical
• Vascular decompression (Janetta Procedure)
• Relieves pressure on the trigeminal nerve root by usually by the
superior cerebellar artery
• Percutaneous glycerol injection
• Radiofrequency rhizotomy
• Gamma knife: localize and burn off nerve (can come back)
Sensory but no motor problems
CM 4- Cranial Neuropathies
Facial Nerve Palsy (Bells palsy)
• Clinical presentation
– Unilateral facial weakness
– Other associated features
• Hyperacusis on the affected side
• Ear pain
• Derangement in taste (ant 2/3 tongue)
• Mechanism
– Inflammation, compression, demyelination or infarct of the seventh cranial nerve
• Bell’s Palsy is “idiopathic”, but it is presumed to be due to viral infection (likely
herpes simplex)
• Can be seen with Lyme disease (often bilateral)
• Bilateral facial nerve palsy can also be seen with sarcoidosis (a granulomatous
disorder)
• Melkersson Syndrome
• Recurrent facial nerve palsies associated with swelling of the lips,
eyelids, and face
• Evaluation
– Clinical history and examination are most important
– Appropriate testing if some other cause of the facial nerve palsy is suspected
• MRI brain
• Laboratory studies
• Other imaging studies (chest X-ray if concerned about sarcoidosis
• Treatment
– Most patients will recover without therapy
– Recovery time may be reduced with steroid therapy and antiviral therapy
• Prednisone tapered over about 3 weeks
• Antiviral medication such as acyclovir for 7 to 10 days
– Monitor for evidence of corneal irritation due to inability to close the eye (especially at
night) – cannot blink due to the nerve damage
• Prognosis
– 70% recover completely
– Initial improvement can be seen as early as three weeks for 85% of affected individuals
• It may take up to three to six months to begin to see improvement
Mainly Motor with little sensory problems
CM 4- Cranial Neuropathies
Glossopharyngeal Neuralgia
• Clinical presentation
– Paroxysmal, unilateral pain in and around the throat, jaw, ear, larynx, or tongue in the
distribution of the glossopharyngeal and vagal nerves
– Deep aching pain may be present between bouts
– Triggers
• Coughing
• Swallowing
• Yawning
• Cold liquids
• Stimulation of the external auditory canal
• Mechanism
– Usually due to vascular compression or other structural abnormality
• Evaluation
– Diagnosis is usually made clinically and with appropriate imaging studies (MRI brain) to
look for
• Cerebellopontine angle tumor
• Nasopharyngeal carcinoma
• Peritonsillar abscess
• Osteophytic stylohyoid ligament (Eagle Syndrome)
– In 90% of affected individuals, local anesthetic applied to the region of the tonsils and
pharynx terminates the pain
• Treatment
– Medications useful for neuropathic pain (as in trigeminal neuralgia)
– Refractory cases may require intracranial sectioning of the glossopharyngeal nerve and
upper rootlets of the vagal nerve at the jugular foramen
Chronic Paroxysmal Hemicrania
• Clinical presentation
– May be a variant of cluster headache
– Unilateral paroxysms of pain localized to the temporal, frontal, ocular, aural, or
maxiallary region
• Pain is typically stabbing, boring, or throbbing and is moderate to severe in
intensity
• Attacks last for 2 to 25 minutes (usually shorter than cluster) and can occur up
to 40 times a day (average of 10-20 per day)
• Can be associated with autonomic features (like cluster)- nose stuffy, eye red
• Evaluation
– Diagnostic studies to consider
• CT or MRI of the brain
• Angiography
• Insure no ocular pathology (glaucoma)
• Treatment
– Usually responds well to indomethacin 25 to 50 mg up to three times a day
• Monitor for GI complications
– Can consider a preventive therapy used in migraine or cluster headaches
CM 4- Cranial Neuropathies
Carotodynia
• Clinical presentation
– Unilateral pain arising from the region of the cervical carotid artery, frequently arising
from the jaw, face, ear, and head
• The pain can be stabbing, throbbing, or dull and can last days to weeks
– Pain can become chronic
• Tenderness, pulsations, and soft tissue swelling along the ipsilateral carotid
artery are common
• Mechanism
– Primary mechanism may be similar to migraine and, in fact, may represent a migraine
variant
• Evaluation
– Must exclude other causes of head and neck pain
• Temporal arteritis
• Carotid artery dissection
• Thyroiditis
• Tumor
• Temporomandibular joint dysfunction
• Otitis/mastoiditis
– Diagnostic studies to consider
• Carotid ultrasound
• MR or CT angiography of the carotid arteries
• MRI or CT of the soft tissues of the neck
• MRI of the brain
• Laboratory studies (e.g. ESR)
• Treatment
– Acute syndrome
• NSAIDs
• Analgesics
• Migraine specific medications (triptans)
• Steroids may be helpful
– Chronic syndrome
• Indomethacin 25-50 mg three times a day
• Preventive medications used for migraine
– Beta blockers
– Tricyclic antidepressants
– anticonvulsants
CM 4- Cranial Neuropathies
Carotid Artery Dissection
• Clinical presentation
– Acute neck and head pain in the presence of stroke-like neurological symptoms
• Neurological symptoms may be transient or permanent deficits may be delayed
and may include
– Ipsilateral Horner syndrome
– Any deficit from disruption of blood flow
– Evidence of subarachnoid hemorrhage from leaking of blood
intracranially from dissection
– May her a carotid or ocular bruit
– Most cases occur in individuals 45 years or younger
• Mechanism
– Apparent weakness of the arterial wall which results in separation of the internal elastic
lamina from the medial layer
– Blood extravasates into the arterial wall and produces a hematoma and occlusion of the
lumen
– May be caused by trivial trauma
• Coughing, straining, various neck movements
• Roller-coaster rides
• Evaluation
– The most important thing is to include this condition in the differential diagnosis
• Because of the neurological deficits, the tendency is to focus on the intracranial
pathology and to overlook the neck vasculature
– MRI of the soft tissues of the neck
– MR or CT angiography of the carotid arteries
– May need to consider doing a lumbar puncture to look for subarachnoid hemorrhage
• Treatment
– Unless there is evidence of intracranial hemorrhage, anticoagulation therapy with
heparin in initiated followed by warfarin for about three months then three months of
antiplatelet therapy
– The dissection usually resolves on its own
– May require surgical intervention
CM 4- Cranial Neuropathies
Post Herpetic Neuralgia
• Clinical presentation
– The acute outbreak of the vesicles is typically preceded by various sensory disturbances
(by 4 to 5 days)
– Most attacks are unilateral in a specific nerve distribution
– After initial eruption pain may persist for weeks to months
• May have severe hyperesthesia
• Allodynia: don’t want to touch face
• May have paroxysms of sharp, stabbing pain
• Mechanism
– the zoster infection produces inflammatory necrosis of the dorsal root ganglion that
extends to the meninges and dorsal root entry zone of the involved segments
• Treatment
– Acute infection
• Oral steroids
• Antiviral agents (acyclovir, famciclovir)
• Analgesics
• Low-dose amitriptyline or nortriptyline may be helpful
– Post herpetic pain may require a combination of therapies to include
• Topical agents
• Lidocaine patch
• Capsaicin cream
• Oral medications
• Tricyclic antidepressants
• Anticonvulsants
• Analgesics
• Neural blockade can be considered