Absence of Meckel Cave: A Rare Cause of Trigeminal Neuralgia.

Trigeminal neuralgia is a debilitating condition with numerous etiologies. In this retrospective case series, we report a cohort of patients with a rarely described entity, absence of Meckel cave, and propose this as a rare cause of trigeminal neuralgia. A search of the electronic medical record was performed between 2000 and 2020 to identify MR imaging reports with terms including "Meckel's cave" and "hypoplasia," "atresia," "collapse," or "asymmetry." Images were reviewed by 2 blinded, board-certified neuroradiologists. Seven cases of the absence of Meckel cave were identified. Seven patients (100%) had ipsilateral trigeminal neuralgia and ipsilateral trigeminal nerve atrophy, suggesting an association between absence of Meckel cave and trigeminal neuralgia. Absence of Meckel cave is a rare entity of unknown etiology, with few existing reports that suggest the possibility of an association with trigeminal neuralgia. Its recognition may have important implications in patient management. Future studies and longitudinal data are needed to assess treatment outcomes and added risks from surgical intervention in these patients.

Takotsubo cardiomyopathy in the setting of acute hydrocephalus secondary to neurocysticercosis.

We report the case of a 45-year-old male who presented with transient neurogenic stunned myocardium, or takotsubo cardiomyopathy, secondary to acute hydrocephalus caused by obstruction of the third ventricle by neurocysticercosis.

Myasthenia gravis with autoimmune autonomic neuropathy.

The autoantibodies that impair neuromuscular junction transmission in myasthenia gravis are specific for the nicotinic acetylcholine receptor (AChR) of muscle. Antibodies specific for AChRs in ganglionic neurons are found in a majority of patients with subacute autonomic neuropathy. Dysautonomia is not a recognized feature of myasthenia gravis, but there have been rare reports of myasthenia gravis coexisting with autonomic failure, usually in association with thymoma. Here we report seven patients who had myasthenia gravis with subacute autonomic failure. Their autonomic dysfunction ranged from isolated gastroparesis to severe panautonomic failure. Gastrointestinal dysmotility was a common feature. All had antibodies against muscle AChR, and three (all of whom had thymoma) had antibodies against neuronal ganglionic AChRs. In several patients, gastrointestinal function improved clinically after administration of an acetylcholinesterase inhibitor. These observations support a rare but definite clinical association between myasthenia gravis and autonomic failure and strengthen the concept that subacute autonomic neuropathy is an autoimmune disorder.

Fosphenytoin: an intravenous option for the management of acute trigeminal neuralgia crisis.

Timely management of trigeminal neuralgia presenting with severe, sustained, crescendo pain can be difficult with oral medications. More rapid pain control often can be achieved using intravenous phenytoin. Fosphenytoin is a phosphate ester prodrug of phenytoin that is significantly better tolerated parenterally than phenytoin in the treatment of epilepsy. Three patients with trigeminal neuralgia refractory to oral medications and presenting with crisis pain were treated urgently with intravenous fosphenytoin. In each case complete relief of pain was achieved for a duration of two days, affording a window of opportunity to modify oral pharmacotherapeutic strategies or to control pain in preparation for invasive neurosurgical intervention.

Headache in divers.

The increasing popularity of scuba diving has added a new category to the differential diagnosis of headache. Headache in divers, while uncommon and generally benign, can occasionally signify serious consequences of hyperbaric exposure such as arterial gas embolism, decompression sickness, and otic or paranasal sinus barotrauma. Inadequate ventilation of compressed gases can lead to carbon dioxide accumulation, cerebral vasodilatation, and headache. Other types of headache encountered in divers include exertional headache, cold stimulus headache, migraine, tension-type headache, acute traumatic headache, cervicogenic headache, carbon monoxide poisoning headache, and headache associated with envenomation. Correct diagnosis and appropriate treatment require a careful history and neurologic examination as well as an understanding of the unique physiologic stresses of the subaquatic environment.

Spinal cord infarction mimicking angina pectoris.

Severe chest pain resembling angina pectoris in a 42-year-old man preceded the development of neurologic signs, distracting from recognition of the acute infarction of the cervical spinal cord responsible for his pain. Consistent with a spinal origin of chest pain were the absence of any evidence of cardiac disease and the demonstration of infarction at C6-7. This segmental level coincides with the convergence of ascending afferent traffic entering the central nervous system from the cardiac plexus. Spinal stroke affecting the lower cervical level can thus mimic the pain of myocardial ischemia.

Hypotensive akathisia: autonomic failure associated with leg fidgeting while sitting.

The author describes a distinct clinical syndrome in six patients with autonomic failure who manifested habitual, voluntary, transiently suppressible, yet irresistible leg movements occurring only in the sitting position. Keeping the legs still brought on vague symptoms of fatigue, lightheadedness, or apprehension. Repetitive leg crossing, muscle tensing, foot twirling or wiggling, or heel or toe floor tapping while sitting may have compensated for orthostatic hypotension and raised systolic blood pressure by a mean of 28 mm Hg and diastolic pressure by a mean of 11 mm Hg.

Idiopathic intracranial hypertension and seventh nerve palsy.

Patients with idiopathic intracranial hypertension may occasionally present with coexisting lower motor neuron facial weakness. This study reviews a 6-year experience at Mayo Clinic. The aim of this study was to determine the possible association of idiopathic intracranial hypertension and facial paresis. Two cases were identified. Both fulfilled the modified Dandy's diagnostic criteria for idiopathic intracranial hypertension. Treatment consisted of steroids in one, and emergent optic nerve sheath fenestration in the other. The cranial nerve palsies resolved in both cases.

Trigeminal neuralgia : a guide to drug choice.

Trigeminal neuralgia, also known as tic douloureux, is an idiopathic condition of severe, unilateral, paroxysmal facial pain. The abrupt nature of the painful attacks (a temporal profile that is similar to that of seizures) led to the discovery that some anticonvulsant drugs are effective against neuralgia.Carbamazepine is the drug of choice, and treatment requires careful dosage titration. Baclofen, phenytoin and sodium valproate are also effective. Transient relief is sometimes possible with local anaesthetics. Limited data suggest that topical capsaicin, and tizanidine, lamotrigine, oxcarbazepine, pyridostigmine and enalapril have helped some patients. While effective, other drugs are limited by their adverse effects; for example, clonazepam is too sedating, pimozide induces extrapyramidal adverse effects, and tocainide and felbamate can cause aplastic anaemia. Phenobarbital (phenobarbitone), opioids, mexiletine, tricyclic antidepressants, corticosteroids, nonsteroidal anti-inflammatory drugs and sympatholytics are ineffective.The antineuralgic effect of any drug may eventually wear off. If this occurs, combination therapy can restore pain relief, as can the reintroduction of a previously effective drug following a drug-free interval.Similar pharmacological strategies potentially apply to other paroxysmal pain syndromes such as vagoglossopharyngeal neuralgia. Clinical overlap with multiple sclerosis or cluster headache suggests additional drugs that may be useful in specific patients. Effective neurosurgical procedures exist for patients with trigeminal neuralgia that is refractory to medications.

An overview of the diagnosis and pharmacologic treatment of migraine.

Migraine, an episodic headache disorder, is one of the most common complaints encountered by primary-care physicians and neurologists. Nevertheless, it remains underdiagnosed and undertreated. Rational migraine treatment necessitates an accurate diagnosis, identification and removal of potential triggering factors, and, frequently, pharmacologic intervention. Effective management also includes establishing realistic expectations, patient reassurance, and education. The choice of medication (abortive, symptomatic) for an acute attack depends on such factors as the severity of the attack, presence or absence of vomiting, time of onset to peak pain, rate of bioavailability of the drug, comorbid medical conditions, and side-effect profile. Effective agents for acute attacks include simple or combination analgesics, nonsteroidal anti-inflammatory drugs, ergot derivatives, selective serotonin agonists, and antiemetics. Opioid analgesics are unnecessary for most patients. The choice of preventive (prophylactic, interval) medication depends primarily on comorbid medical conditions and side-effect profile. Useful preventive agents include beta-adrenergic blockers, calcium channel blockers, tricyclic antidepressants, anticonvulsant medications, and serotonin antagonists.

Spinal cord infarction: etiology and outcome.

We reviewed 44 cases of ischemia and infarction of the spinal cord at two university hospitals. Three patients experienced transient ischemic attacks. Etiologies of completed strokes were diverse and included rupture and surgical repair of aortic aneurysms, aortic dissection, aortic rupture and thrombosis, global ischemia, anterior spinal artery embolism, repair and thrombosis of spinal arteriovenous malformations, hematomyelia, epidural hematoma, cervical osteophytosis, celiac plexus block, systemic lupus erythematosus, coagulopathy, and decompression sickness. Motor function improved in 12 patients, was substantial in only one, and occurred largely within the first 2 to 4 weeks. Favorable ambulatory outcome correlated with improving neurologic examinations and relatively preserved strength in hip abductors and knee extensors. More extensive deficits without initial improvement portended a more severe prognosis. Autonomic dysfunction, pain, paresthesia, and depression were common and impeded recovery in some patients. The mean level of deficit was at T-8 and in cases of global ischemia was at T-9, which leads us to dispute the classical view of a midthoracic watershed zone of ischemic vulnerability near T-4.

Subcutaneous botulinum toxin type A inhibits regional sweating: an individual observation.

Botulinum toxin inhibits neuromuscular transmission by blocking the exocytosis of acetylcholine. It was tested for a similar effect on cholinergic postganglionic sympathetic neurones at the sudomotor junction. Subcutaneous injections of 0.1 and 1.0 units of type A botulinum toxin into the forearm of a healthy subject abolished local thermoregulatory sweating in cutaneous regions spanning 1.0 and 1.5 cm for nearly 1 year without producing weakness. Botulinum toxin, therefore appears to have potent anhidrotic activity.

Angiocentric T-cell lymphoma presenting with multiple cranial nerve palsies and retrobulbar optic neuropathy.

Angiocentric T-cell lymphoma (lymphomatoid granulomatosis) may present with prominent central nervous system (CNS) findings with variable radiographic features. We describe a patient who presented with multiple cranial nerve palsies involving the left optic nerve, left facial nerve, left ocular motor nerves, and bilateral acoustic nerves. Enhancement of the right temporal meninges and a cavernous sinus mass were noted on magnetic resonance (MR) scan. A right temporal craniectomy and meningeal biopsy were performed. Meningeal biopsy revealed atypical angiocentric granulomatous lymphoid infiltrates without associated necrosis, giant cells, or granuloma formation. Morphologic and T-cell, receptor gene rearrangement findings were diagnostic of an angiocentric T-cell lymphoma. Retrobulbar optic neuropathy and multiple cranial nerve palsies may be the presenting features of angiocentric T-cell lymphoma. The neurologic and unique radiographic changes in our case expand the previously reported findings in CNS angiocentric T-cell lymphoma.

Felbamate relieved trigeminal neuralgia.

OBJECTIVE: The analgesic efficacy of the novel anticonvulsant felbamate was evaluated in trigeminal neuralgia. PATIENTS AND SETTING: This trial was offered in a tertiary referral center to three outpatients with severe pain who had exhausted other medical options, yet did not wish to undergo surgery. INTERVENTIONS: Felbamate was prescribed as the sole analgesic for approximately 1 month. OUTCOME MEASURES: A visual analogue scale was utilized. RESULTS: Felbamate potently diminished the severe pain of trigeminal neuralgia and was well tolerated. The drug was withdrawn because of subsequent reports elsewhere of aplastic anemia and hepatic failure associated with it when used for epilepsy. CONCLUSIONS: Preliminary evidence suggested that felbamate was effective in relieving trigeminal neuralgia. Stabilization of neuronal membrane depolarization was the most likely mechanism of action. However, significant potential risks preclude further use of felbamate in the management of nonmalignant pain. Principles that have proven useful in screening for new anticonvulsant drugs might be relevant to the development of methods by which to search for new analgesic drugs.