Relief of cluster headache and cranial neuralgias. Promising prophylactic and symptomatic treatments.

When a patient presents with persistently unilateral head or face pain, cluster headache and trigeminal neuralgia should be considered. Diagnosis is based on the patient's history; anatomical studies are performed only to rule out problems other than tumor or stroke. A patient who presents with pain in the pharynx, tonsils, and ear--particularly if it is initiated by swallowing, yawning, or eating--may have glossopharyngeal neuralgia. Treatment with carbamazepine is indicated; if the patient does not respond to this drug, the diagnosis is doubtful. Several effective treatments are available for these conditions. Oxygen, drug therapy, or surgery may be indicated depending on the course of the disease.

Identification and treatment of sleep apnea in patients with chronic headache.

This study investigates the relationship between nocturnal or morning headache and obstructive sleep apnea syndrome (sleep apnea). It is not known if headache of any type is more common in patients with sleep apnea than in other patients, but morning headache is a symptom of sleep apnea. A method is needed for identifying patients with chronic headache who might benefit from evaluation and treatment of sleep apnea. We performed a retrospective assessment of frequency of morning headache in patients grouped according to final diagnosis: sleep apnea (n = 72), periodic leg movements of sleep (n = 28), and psychophysiologic insomnia (n = 42). Prospective overnight sleep studies were obtained in a different group of 19 patients who presented for evaluation of headache. We selected certain patient characteristics as possibly indicative of sleep apnea-related headache. The retrospective study showed that 24% of patients with sleep apnea had frequent morning headache, which was not different from the other groups. In the separate group of 19 patients with chronic headache and suspected sleep disorder, 17 had sleep apnea. Nasal continuous positive airway pressure was prescribed to 14 patients. Marked improvement in headache occurred and persisted in 4 patients and moderate improvement in 3. Responders to therapy were more likely to have vascular headaches than mixed or tension headaches, more severe sleep apnea, and a nocturnal or morning timing to their headaches. However, there was large overlap in severity of sleep apnea and likelihood of response. We conclude that morning headache is not more common in sleep apnea than in other sleep disorders. However, over 30% of patients with chronic headache and other symptoms of sleep apnea have significant improvement in headache after treatment of sleep apnea.

Non-invasive trigeminal evoked potentials: normative aging data.

A mild electric shock applied to the lower lip was used to elicit reliable evoked potentials from the trigeminal nerve in 50 normal adults who ranged in age from 20 to 69 years. The waveforms were morphologically similar to those observed with invasive procedures. No substantial effects for subject age, side of stimulation, or recording electrode were obtained for any of the individual trigeminal evoked potential amplitudes or latencies. Female subjects tended to have somewhat larger amplitudes and shorter latencies than male subjects. The results suggest that non-invasive procedures produce reliable evoked potential measures of trigeminal nerve function for patients of all ages.

Diagnosing the severe headache.

A patient's medical history, age of onset, location of pain, pain characteristics, pain chronology, associated signs and symptoms, and signs of neurologic dysfunction are all important considerations in making a diagnosis. The International Headache Society has developed a thorough classification system to aid in the diagnosis of headache, which includes primary disorders of migraine, tension-type headache, and cluster headache, as well as secondary, organic disorders.

Transcranial Doppler ultrasound and magnetoencephalography in migraine.

Eighty subjects--30 migraineurs during the attack, 30 patients in the interictal period, and 20 healthy volunteers--were studied using two technologies for functional assessment: transcranial Doppler ultrasound and magnetoencephalography. Transcranial Doppler studies showed an increased mean flow velocity at rest (p less than 0.05) in the middle cerebral artery on the side of the headache and a decreased vasomotor response to CO 2 (p less than 0.001) on the same side compared to control subjects. Biomagnetic measurements of somatosensory evoked fields of 11 patients and 11 control subjects in this study did not demonstrate differences between migraineurs and the control group in current flow or latency measures. The data from this study tend to support the hypothesis of vascular disease as a primary underlying deficit in migraine.

P300 in multiple sclerosis: a preliminary report.

The P300 component of the event-related brain potential (ERP) elicited with auditory stimuli and pattern-shift visual evoked potentials (VEPs) was obtained from 16 patients with multiple sclerosis (MS) and 16 matched control subjects. P300 latency was significantly longer and component amplitude relatively depressed in the MS patients compared to control subjects. The P100 potential of the VEP also was delayed for both full-field and half-field stimulus conditions in the patients compared to control subjects. The findings suggest that the P300 ERP may reflect the cognitive decline associated with MS.

Diagnosis and treatment of cranial neuralgias.

Both medical and surgical therapies may be used in the treatment of trigeminal neuralgia and glossopharyngeal neuralgia. Ordinarily, the treatment is medical; however, if a response to drugs is not forthcoming, or if the patient becomes toxic while taking medications or refuses to abide by an appropriate medical program, then surgical consultation should be obtained and the appropriate operation performed. The form and type of neurosurgical procedure will probably depend to a considerable extent on the expertise of the neurosurgeon and his training. Generally, in the elderly, the simplest procedure should be attempted first. It may be necessary to employ both medical and surgical procedures in the individual patient. The medical drug of first choice is carbamazepine. Atypical facial neuralgia is a general term used to cover a variety of head and face pains that are poorly defined and that may not deserve separate clinical status. The pathogenesis of the atypical facial neuralgias is uncertain, and multiple causation seems likely. Search for local inflammatory pathology, neoplasms, vasomotor phenomena, and depressive symptoms is indicated. Treatment should be guided by the findings.

Noninvasive trigeminal evoked potentials: normative data and application to neuralgia patients.

A mild electric shock applied to the lower lip was used to elicit reliable evoked potentials from the trigeminal nerve in 20 normal young adults. The wave forms were morphologically similar to those observed with invasive procedures. No substantial differences for either the right or left side of stimulation, recording electrode, or subject sex were obtained for any of the individual potential amplitudes or latencies. The same procedures were applied to 10 patients who had been treated with retrogasserian glycerol injections for trigeminal neuralgia. Trigeminal evoked potentials were elicited in all patients, although the quality of the individual wave forms was more variable than that observed for the normal subjects. Comparison of the treated with the unaffected face side in the patients demonstrated significantly smaller N2-P2 amplitudes and longer N2 latencies for the affected face side. The results suggest that these procedures produce reliable evoked potential measures of trigeminal nerve function noninvasively which can provide an objective index of treatment efficacy.

The pathology of migraine.

It is well established that multiple influences regulate cerebral blood flow; the overwhelming evidence continues to suggest that migraine is a disorder, albeit temporary, of cerebral hemodynamics. Thus, the classical theory of migraine is no longer tenable as viewed strictly and rigidly. Perhaps it would be easier to say that the migraine's aura is characterized by reduction in blood flow, often hemispheric, and that sometime during the headache phase cerebral hyperperfusion occurs. The process is under the control of multiple factors: neurogenic, chemical, metabolic, and myogenic. The blood flow changes do not necessarily correlate with the patient's symptoms. Thus, even now, migraine and other vascular headaches remain as descriptive diagnoses. The final pathology of migraine remains to be determined.

Percutaneous injection of glycerol for the treatment of trigeminal neuralgia.

There continues a significant debate over the best contemporary method for treating trigeminal neuralgia. Glycerol injection into the trigeminal cistern has been used in a consecutive series of 200 patients. A total of 80% of the patients have had good or excellent pain relief. Side effects have been a mild and usually transient numbness and tingling or mild objective sensory deficit to pin and touch in approximately 1/2 of the patients. Complications have been extremely infrequent and have resolved in time. A recurrence rate of 24% has been the single largest disadvantage of the procedure. Reinjection is usually successful in treatment of recurrence. The combination of efficacy, minimal and temporary neurologic dysfunction, and low complication rate make this procedure, in our opinion, the procedure of choice for the first step, when surgical treatment is required.

Long latency auditory evoked potentials: intensity, inter-stimulus interval, and habituation.

Experiment 1 elicited the P1, N1, P2, and N2 components of the long latency auditory evoked potential (AEP) using a 1000 Hz tone presented at 30, 50, or 70 dB SPL and 1-, 3-, or 5-second inter-stimulus intervals to assess the relative effects of the combination of these variables on component amplitude and latency. Four blocks of 16 tone presentations each were recorded from each subject to determine if changes in the AEP would occur because of short-term habituation. Both stimulus factors interacted significantly in a systematic fashion for the amplitude measures, with increases in latency also associated with increases in intensity and inter-stimulus interval. Only minor changes across the four trial blocks for either the amplitude or latency measures were observed over the various stimulus presentation conditions. Experiment 2 employed the same tone stimulus presented at 50 dB SPL and a 3-second inter-stimulus interval. Eight blocks of 64 trials were recorded from each subject on each day for four days to investigate long-term habituation effects. No substantial changes in any of the component amplitudes or latencies were obtained across the 32 trial blocks. It was concluded that intensity and inter-stimulus interval interact to determine AEP amplitude as well as latency values and that the constituent components do not change appreciably with repeated stimulus presentations, even after several days.