Microvascular decompression as a treatment for cranial nerve hyperactive dysfunction--a critical view.

Neurovascular compression has been postulated as a probable mechanism for a large number of cranial nerve syndromes, with trigeminal neuralgia (TGN) as the prime example. Microvascular decompression (MVD) is often cited as the procedure of choice for treatment of medically refractory TGN. Arguments against these assumptions are: MRA studies indicate that vascular contact with the trigeminal nerve is present in most healthy individuals. Treatment results of MVD in multiple sclerosis patients with TGN are almost as good (at least in the short term) as in idiopathic cases. MVD is reported to provide pain relief even in TGN patients without visible neurovascular contact . In other syndromes of cranial nerve'hyperactive dysfunction'--vertigo, tinnitus and neurogenic hypertension--the documentation is even weaker.

Absence of focal neurological involvement in tick-borne relapsing fever in northern Tanzania.

The aim of the study was to chart incidence and clinical features of tick-borne relapsing fever in Tanzania. Consecutive patients with fever and spirochetes demonstrated in a thick blood smear at Haydom Lutheran Hospital from 1 January to 31 December 2003 underwent clinical and cerebrospinal fluid (CSF) examination. Forty-four patients were included, making an estimated minimum annual incidence of 11 per 100 000 population in this region. The mortality rate was 2.3% (95% CI = 0-12). The most frequent complaints were generalized malaise (93%), headache (86%), nausea and vomiting (52%). None of the patients [0% (95% CI = 0-8)] had focal neurological symptoms. Cell count in CSF was normal in 22 and slightly elevated (6-12 leukocytes/mm(3)) in 20 patients. Two of three pregnancies had a poor outcome. Jarisch-Herxheimer reactions, bleeding complications and ocular manifestations were infrequent. In conclusion, tick-borne relapsing fever is a common disease in the Northern highland of Tanzania, but in contrast to other parts of the world, neurological involvement is uncommon in this area.

Onset and course of chronic inflammatory demyelinating polyneuropathy.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is clinically heterogeneous. Our purpose was to determine whether initial progression time, clinical features, and distribution of nerve conduction slowing at presentation correlate with clinical course and prognosis. We examined how findings at presentation related to clinical course during an average follow-up time of 4.0 (range 1.0-9.0) years in 44 patients with CIDP. We calculated terminal latency index (TLI), a measure of differential slowing in distal relative to more proximal nerve segments. Patients with acute or subacute onset (progression over less than 8 weeks) had a higher remission rate (P = 0.012) than patients with chronic onset (progression over more than 8 weeks). Patients with proximal weakness had a higher remission rate than patients with the distal phenotype (P < 0.001). All 5 patients with a relapsing course had subacute onset. They had lower TLIs, suggesting a more distal pattern of demyelination, than patients with a monophasic or chronic course. In conclusion, subacute onset and presence of proximal weakness are good prognostic signs that correlate with a high rate of recovery to normal in CIDP. Distal accentuation of conduction slowing at presentation correlates with subacute onset and a relapsing course.

Chronic polyneuropathies in Vest-Agder, Norway.

Epidemiological data on chronic polyneuropathies, especially inflammatory types, is limited. The purpose of this study was to examine the spectrum of causes and estimated prevalence of various polyneuropathy types in Vest-Agder, and to examine the clinical features of the Vest-Agder population of chronic inflammatory demyelinating polyneuropathy (CIDP). In Vest-Agder county (population of 155 464), polyneuropathy patients are registered in a database and followed prospectively. We did a measure of the database on October 31 1999. A total of 192 patients were registered. The prevalence for chronic inflammatory demyelinating polyneuropathy (CIDP) was 7.7 per 100 000 population. The course was relapsing in five of fifteen patients, progressive in four patients and slowly progressive in six of fifteen patients. Two of the fifteen patients had pure sensory symptoms. The mean Rankin disability score was 3.4 at maximal deficit and 2.1 at last follow-up. The prevalence of paraproteinemic polyneuropathy was 5.1 per 100 000 population. None of the patients with paraproteinemic polyneuropathy were worse than slightly disabled (disability score < or = 2). The prevalences for other polyneuropathies were as follows: polyneuropathy and RA, 1.3; polyneuropathy and Sjögren's syndrome or sicca complex, 4.5 (polyneuropathy was the presenting symptom in five of seven patients); sarcoidosis 1.9; polyneuropathy and chronic Lyme, 0.6; paraneoplastic polyneuropathy, 1.9; diabetic polyneuropathy 23.2; vitamin deficiency, 5.1; alcoholic and toxic polyneuropathy, 19.9; hereditary polyneuropathy, 14.8. Cryptogenic polyneuropathies made up 26% of all polyneuropathies. The mean disability score was 2.0 (SD 1.1). In conclusion, prevalence of CIDP was significantly higher than previously reported, and the prognosis was good in the majority of patients. Patients with paraproteinemic polyneuropathy were not severely disabled. Polyneuropathy was the presenting symptom in the majority of patients with Sjögren's syndrome or sicca complex.

Cardiovascular changes associated with spontaneous and evoked K-complexes.

This study examines the relationship between blood pressure and spontaneous and sound-evoked K-complexes (KCs) during stage 2 NREM sleep, in 8 volunteers studied by intraarterial blood pressure (BP) monitoring and polysomnography. A robust oscillation of blood pressure with a period of 16-30 s (Mayer waves) was seen in all subjects. Spontaneous KCs predominantly occurred during a drop (downward slope) in blood pressure. Randomly administered sound stimuli were more likely to evoke a KC if the stimulus was given during a downward slope of BP. During the last 20 s prior to a sound-evoked KC, the mean drop in systolic BP was 0.3 mmHg, and evoked and spontaneous K-complexes were preceded by a mean drop in BP of 1.9 and 2.7 mmHg, respectively. Finally, K-complexes, either spontaneous or evoked, during the first 6 s, induced a rise in systolic BP. The results indicate that if the BP falls during stage 2 NREM sleep, there is a greater likelihood that an external stimulus will evoke a K-complex and that spontaneous K-complexes may occur more frequently as well. Spontaneous and evoked K-complexes may play a role in the control of BP during NREM sleep.

[Transformed migraine--chronic daily headache]. / Transformert migrene--kronisk daglig hodepine.

Transformed migraine is probably a common cause of chronic daily headache. The International Headache Society system of diagnostic classification of headache classifies headaches, not patients, and pays no attention to the long-term evolution of the patient's headache. We support the suggestion made by Silberstein et al. that transformed migraine should be used as a diagnostic label in patients suffering from chronic daily headache with "migrainous features" and a history of migraine. Since 1994, intravenous treatment with dihydroergotamine (DHE) has been used for these patients. Among 16 patients suffering from chronic daily headache which were treated with this drug in 1996, 10 patients reported complete relief of headache at discharge from the hospital, but only four patients experienced complete relief from headache for more than two weeks. We think that the most important treatment for these patients are medicament withdrawal, information, help and support so that patients may cope with their headache. Dihydroergotamine can help patients going through a withdrawal regime.

[Slow replenishment of carnitine level after long-term treatment with pivampicillin/pivmecillinam]. / Langsom gjenoppbygging av karnitinnivå etter langtidsbehandling med pivampicillin/pivmecillinam.

Long-term treatment with pivampicillin and pivmecillinam for 6-24 months in five adults and one child reduced the total serum carnitine concentrations to 3.7-14.0 mumol/l (reference value 25-66 mumol/l). The muscle carnitine was reduced to 0.3-0.7 mumol/g wet weight (reference value 3-5 mumol/g) in two cases. All patients had asthenia and muscle symptoms with weakness and pain. One showed signs of carnitine depletion in the liver, with increased secretion of dicarboxylic acids (C6, C8, C10) in urine and limited ketone body formation during prolonged fasting (32 hours). The serum carnitine increased slowly after cessation of therapy and reached normal concentrations after 6-12 months. All symptoms caused by carnitine depletion disappeared after the serum carnitine reached 20 mumol/l. This was achieved on a normal diet without carnitine supplement.

Slow replenishment of carnitine deficiency after cessation of long-term treatment with pivaloyl-containing antibiotics.

Long-term treatment with pivampicillin and pivmecillinam for 6-24 months in five adults and one child reduced the total serum carnitine concentration to 3.7-14 mumol/l (reference value: 25-66 mumol/l). Muscle carnitine was reduced to 0.3-0.7 mumol/g wet weight (reference value: 3-5 mumol/g) in two cases. All patients had muscle symptoms with weakness, asthenia and pains. One showed signs of carnitine depletion in the liver with increased secretion of dicarboxylic acids (C6, C8, C10) in urine and limited ketone body formation during prolonged fasting. Serum carnitine increased slowly after cessation of therapy and reached normal concentrations after 6-12 months. All symptoms caused by carnitine depletion disappeared. This was achieved on a normal diet without carnitine supplementation.

Mitochondrial diseases and myopathies: a series of muscle biopsy specimens with ultrastructural changes in the mitochondria.

From 1986 to 1991, 472 muscle biopsy specimens from patients from different hospitals in Norway were examined. Of these, 364 were embedded for electron microscopy, and 194 were examined with electron microscopy. Ultrastructural alterations in the mitochondria were detected in 49 of these specimens. Characteristic electron microscopic findings included subsarcolemmal accumulation of abnormal mitochondria of various shapes and sizes, often containing electron-dense granules and sometimes lipid vacuoles in the mitochondria and diffusely electron-lucent matrix space. Paracrystalline inclusion bodies were seldom seen in specimens from young patients, but in some cases mitochondrial electron-dense granules at the cristae were found. These amorphous densities are consistent with lipoproteins, suggesting that they may represent an early stage of paracrystalline inclusions. Biochemical and genetic exploration of the patients with biopsy specimens suggesting mitochondrial disease indicated maternally genetic inheritance and an enzyme defect in the respiratory chain in 21 patients in two families. Three patients had MELAS syndrome, 7 Marinesco-Sjögren syndrome, and 2 Kearns-Sayre syndrome. Five family members had ptosis, cardiomyopathy, mild myopathy, and increased lactate in cerebrospinal fluid and serum. In addition to the diseases mentioned above, changes in the mitochondria were detected in other conditions such as Rett's syndrome (n = 1), ornithine transcarbamylase deficiency (n = 2), and hypothyroidism (n = 2) as well as in 3 patients with clinical and laboratory results indicative of inflammatory myopathy and 3 patients with clinical and laboratory findings consistent with peripheral neuropathy. It is concluded that, although ultrastructural changes in the mitochondria may represent unspecific findings, electron microscopic examination of muscle biopsy specimens is a useful screening method to select specimens for further biochemical analysis and to obtain an early and more precise diagnosis of the disease.

The clinical significance of sleep apnoea in workers exposed to organic solvents: implications for the diagnosis of organic solvent encephalopathy.

Among 51 patients referred for investigation of possible organic solvent encephalopathy 20 (39%) had pathological sleep apnoea [apnoea index (AI) greater than 5], compared with 5 of 16 house painters exposed to solvents (31%) who were screened for the disorder, and 1 of 18 (6%) age-matched controls. Twelve of the patients with AI greater than 5 were retested after 2 or more weeks without exposure to solvents, and showed a significant drop in AI. Likewise, significantly lower AI was seen in patients who were no longer exposed to solvents, compared with recently exposed patients. The implications of these findings for diagnostic evaluation of solvent encephalopathy and sleep apnoea are discussed.

CSF hydrodynamics after subarachnoid hemorrhage.

Recent reports have shown that despite an apparently satisfactory recovery from previous subarachnoid hemorrhage (SAH), many patients still have minor sequelae when specifically looked for. The cause of this so-called post-SAH-encephalopathy is uncertain. This prospective study comprises 54 patients who underwent aneurysmal surgery after SAH between September 1978 and March 1985. One patient died, and 6 patients were non-biased drop-outs. CSF hydrodynamics, determined by infusion test and isotope cisternography, were evaluated on the remaining 47 patients in the recovery stage. Five patients (11%) were found to have typical clinical, CSF dynamic and radiological manifestations of normal pressure hydrocephalus (NPH), and all were shunted with good results. Twelve (26%) had abnormal results consistent with disturbed CSF-hydrodynamics, although there were no clinical or radiological findings supporting the diagnosis of shunt-demanding NPH. Disturbed CSF-hydrodynamics as one of the possible etiological factors of post-SAH-encephalopathy is discussed.

Sleep apnoea and organic solvent exposure.

Fifteen patients referred for the evaluation of possible organic solvent encephalopathy were studied by clinical polysomnography. Seven had more than 30 apnoeas per night and an apnoea index of higher than 5, thus fulfilling the commonly used criteria of the sleep apnoea syndrome. Another group of eight workers exposed to trichlorethane, examined without prior knowledge of their individual symptoms, showed a significantly elevated number of sleep apnoeas compared with nine controls. The results indicate that organic solvent exposure can cause sleep apnoea.

The uptake, storage, and efflux of serotonin in platelets from migraine patients.

A recently developed method for analysing 5-hydroxytryptamine (5-HT) efflux from platelets preloaded with a small amount of 14C-5-HT enables the assessment of the relative size of the granular and the cytoplasmatic pools of 5-HT within the platelets and of the rate of spontaneous efflux from these two compartments. This method, together with conventional assessment of the 5-HT uptake measures Km and Vmax, was applied in this study, comparing platelets from 14 patients with common migraine and 10 patients with classic migraine with platelets from 25 healthy controls. All patients were unmedicated and in an attack-free period. Neither the total patient group nor either of the two subgroups differed significantly from the control group on any measure of 5-HT uptake or efflux. However, two differences approached the conventional significance level: the relative size of the granular compartment (Compartment III) was larger for classic than for common migraine, and the efflux rate from Compartment III was shorter for classic migraine than for the healthy controls (P approximately 0.10 in both cases). Further studies are required to show whether these differences are real and, if so, whether they have any relevance for the pathogenesis of migraine attacks.