Influence of personalized extended interval dosing on the natalizumab wearing-off effect - a sub-study of the NEXT-MS trial.

BACKGROUND AND OBJECTIVES: Wearing-off symptoms during natalizumab treatment in multiple sclerosis are characterized by an increase of MS-related symptoms prior to natalizumab administration. The influence of extended interval dosing (EID) on wearing-off symptoms are important to consider, as this might cause hesitancy in initiating or continuing EID. METHODS: Participants of the NEXT-MS trial, in which treatment intervals are adjusted based on drug concentrations, were divided into two groups: an extended group containing participants with at least one week of additional interval extension, and a group with a fixed interval during the trial (range 4-7 weeks). Changes in the occurrence, frequency, onset, and severity of wearing-off symptoms were evaluated. RESULTS: 255 participants were included (extended group n = 171, fixed group n = 84). The odds on occurrence of wearing-off symptoms in the extended group did not increase after extending the treatment interval. Additional analyses for frequency, onset, and severity of wearing-off symptoms showed no changes over time. Mean decrease in natalizumab drug concentration did not influence the frequency of wearing-off symptoms. DISCUSSION: Wearing-off symptoms were not reinforced by further extending the natalizumab interval. Wearing-off symptoms might increase in a minority of patients after EID, although our data support the view that wearing-off symptoms appear to be unrelated to the decrease in natalizumab trough drug concentrations.

Hypotension in anaesthetized patients during aneurysm clipping: not as bad as expected?

BACKGROUND: Patients with aneurysmal subarachnoid haemorrhage (SAH) often have disturbed autoregulation of cerebral blood flow. A reduction in systemic blood pressure during surgery may therefore lead to delayed cerebral ischaemia (DCI). To assess the incidence and severity of intra-operative hypotension, we performed a retrospective cohort study in 164 patients with recent SAH and surgical clipping of the aneurysm. METHODS: Intra-operative hypotension was defined in three levels of severity, as a decrease in mean arterial pressure (DeltaMAP) of more than 30%, 40% or 50% compared with the pre-operative pressure. For each patient the total amount of time with intra-operative hypotension was retrieved. Logistic regression analysis was performed to study the relation between intra-operative hypotension and the occurrence of DCI and poor outcome. RESULTS: A period with DeltaMAP>30% occurred in 128 patients (78%) with a median duration of this period of 105 min (25-75 per thousand 50-171 min). DeltaMAP>40% occurred in 88 patients (54%) and DeltaMAP>50% occurred in 22 patients (13%). In univariate analysis, DeltaMAP>50% was associated with poor outcome. After adjusting for age and World Federation of Neurological Surgeons grade, the association with poor outcome was no longer statistically significant [odds ratio (OR) 1.018; 95% CI 0.996-1.041]. CONCLUSION: Hypotension during surgical clipping of intracranial aneurysms occurred frequently. In our study population of patients mostly in good clinical condition, hypotension was not confirmed as an independent risk factor for DCI or poor outcome. Anaesthesia may have had a cerebral protective effect.

Diagnostic value of myotactic reflexes in axonal and demyelinating polyneuropathy.

In 11 patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and 11 patients with chronic idiopathic axonal polyneuropathy (CIAP), absent myotatic reflexes were significantly associated more often with CIDP than with CIAP, an absent biceps-reflex having the highest sensitivity and specificity for the diagnosis of CIDP. In CIDP, the latencies of electromyographically recorded myotatic reflexes often indicated demyelination, notwithstanding normal clinically assessed myotatic reflexes. Myotatic reflexes may therefore be useful for the distinction between axonal and demyelinating polyneuropathy.

Indications for an immune-mediated etiology of idiopathic sensory neuronopathy.

To investigate immune mechanisms in the etiology of idiopathic sensory neuronopathy (ISN), we studied neurite outgrowth inhibition and antibody binding to neuronal tissue of serum from 4 patients with ISN. Rat dorsal root ganglion (DRG) cells were cultured in the presence of serum from ISN patients and controls. After 48 h of incubation, neurite outgrowth was quantified with a neurofilament ELISA. Serum from ISN patients significantly inhibited DRG neurite outgrowth compared to controls. ISN serum also strongly immunostained fixed cultured and cryostat rat DRG neurons (at dilutions up to 1:10,240), whereas serum from controls did not. Western blots showed unique binding patterns to DRG proteins in 3 ISN patients compared with controls, but a single band corresponding in all ISN patients was not found. The inhibitory effect of ISN serum on neurite outgrowth and the presence of circulating anti-DRG antibodies in the acute phase of the disease supports an immune-mediated pathogenesis of ISN.

Prediction of outcome after resuscitation in a case of electrocution.

Electrical shocks commonly cause widespread acute and delayed tissue damage. Cardiac arrhythmias and respiratory arrest are the most life-threatening complications in the acute phase. Prediction of outcome after cardiopulmonary resuscitation is usually based on neurological findings compatible with anoxic encephalopathy. This report describes a case of electrocution followed by cardiopulmonary resuscitation. Although neurological signs on admission pointed towards severe brain injury, the patient fully recovered and was able to resume the level of cognitive functioning prior to the accident.

Sensory neuropathies including painful and toxic neuropathies.

In most peripheral neuropathies, dysfunction of motor and sensory nerve fibres is present. However, in some of them either pattern may predominate or be exclusively present. In this review we describe the clinical characteristics of sensory neuropathies, with emphasis on their possible causes. Guidelines are given for the diagnostic approach in these patients and, where possible, suggestions are given for treatment, including symptomatic treatment of painful neuropathies.

Response to intravenous immunoglobulin treatment in chronic inflammatory demyelinating polyneuropathy with only sensory symptoms.

In an open prospective study we analysed the effect of treatment with intravenous immunoglobulin (IvIg) in three patients with clinically pure sensory neuropathy, two of whom met the clinical, electrophysiological, pathological and cerebrospinal fluid research criteria of the American Academy of Neurology for chronic inflammatory demyelinating polyneuropathy. In all patients, subclinical signs of demyelination were present in motor nerves. Treatment with IvIg resulted in improvement of neurological functions in all three patients and in improvement of the disability score in two of them.

Development of weakness in patients with chronic inflammatory demyelinating polyneuropathy and only sensory symptoms at presentation: a long-term follow-up study.

This long-term follow-up study examined patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and only sensory symptoms at first presentation, with emphasis on the development of motor symptoms and long-term disability. From all CIDP patients referred to our Department between 1987 and 1995, seven had only sensory symptoms at first clinical presentation. These were investigated according to a standard protocol, including a quantified clinical neurological examination and nerve conduction studies. The mean duration of the disease before weakness developed was 3.1 years, but varied considerably (0.8-6.3 years). At follow-up, weakness developed in five patients and persisted in three of them. Five patients were not seriously incapacitated by their disease (Rankin 1 or 2), four of them being in remission now and one showing a very slow progression of disease. Two patients were moderately disabled (Rankin 3); one had severe persistent sensory ataxia and only weakness during relapses and one had stepwise progression and moderate weakness. Motor nerve conduction studies revealed that the most notable worsening in the entire group of patients was a decrease in distal compound muscle action potential amplitudes, indicating the development of distal conduction block or axonal degeneration. These findings show that CIDP with only sensory symptoms is a transient clinical stage that precedes the appearance of weakness in about 70% of patients. The long-term prognosis does not differ from that of patients with CIDP who have weakness at the beginning of the disease.

How do general practitioners diagnose and manage patients with transient monocular loss of vision of sudden onset?

Symptoms of transient loss of vision in one eye differ widely. They may have different causes and therefore carry a different prognosis. We studied the influence of differences between characteristics of transient monocular blindness on the diagnosis and management by general practitioners (GPs). A postal questionnaire, was sent to 1600 GPs in The Netherlands along with four case vignettes describing a case history of a 56-year-old man with transient monocular disturbances of vision of sudden onset. We introduced random permutations in the following four elements of the history: partial or complete visual field involved, blurring or blacking out of vision, attacks lasting minutes or hours, and patients having covered either eye during the attack or not. Respondents were asked about the probable diagnosis and the preferred management. For each of the 16 permutations about 50 responses were obtained (overall response rate 54%). Ischemic transient monocular blindness (ITMB) was chosen as the most likely diagnosis in 49%. In 12% primary ocular disease was suspected. Involvement of the complete visual field, blacking out of vision, and short attacks were identified as independent predictors of a diagnosis of ITMB. A diagnosis of ITMB would have resulted in referral to a specialist in 72% of patients. Antithrombotic treatment would have been initiated in only 36% of ITMB patients. GPs consider brief attacks with complete blacking out of vision most typical for retinal ischemia. They refer only three-quarters of patients with probable ITMB to a specialist and start antithrombotic medication in only one-third of these patients. Therefore further education with regard to transient monocular blindness is needed.

[Pain in the legs and progressive neurological deterioration: tethered cord syndrome in adults]. / Pijn in de benen en progressieve neurologische uitval: gekluisterd-ruggenmergsyndroom bij volwassenen.

In four patients, women aged 58, 63 and 42 years, and a man aged 25 years, tethered cord syndrome was diagnosed. These patients suffered from progressive neurological symptoms, notably radiating pain in the legs in the first three patients, and muscle weakness and atrophy in the lower legs in the fourth patient. All four were treated surgically. Nowadays, the phrase tethered (spinal) cord is used for both occult and open closure defects of the neural tube. New neurological symptoms and signs can develop not only in childhood, but also in adults. Neurosurgical release of the tethered cord prevents further deterioration and often leads to significant subjective improvement of symptoms.

[Missing spleen: indication for pneumococcal vaccination]. / Geen milt meer: indicatie voor pneumokokkenvaccinatie.

Two female patients, aged 39 and 52 years, developed severe pneumococcal meningitis. Both patients had undergone splenectomy in the past (one after trauma and one for idiopathic thrombocytopenic purpura) and pneumococcal vaccination was only given immediately after the splenectomy. After antibiotic treatment and intensive care one patient remained disabled and the other patient died. There is a higher risk of developing severe sepsis after splenectomy, with Streptococcus pneumoniae being the causative micro-organism in more than 50% of cases. Vaccination after splenectomy in order to prevent a severe sepsis syndrome is very important. Indications for the 7 valent pneumococcal conjugate vaccine and the 23 valent polysaccharide vaccine are given.

[Totally paralyzed or brain dead?]. / Volledig verlamd of hersendood?

In two patients, men aged 23 and 42 years, a condition that mimicked brain death was observed as a consequence of rapidly progressive complete peripheral paralyses, which included the intrinsic and extrinsic eye muscles. However, the EEG revealed a waking pattern. Maximal supportive therapy was provided, which included haemodialysis for the first patient and artificial ventilation for both patients. A slow recovery was seen after four weeks. The first patient was paralyzed following the ingestion of a large quantity of ethylene glycol and the second by botulism due to the consumption of injudiciously canned food. In patients with catastrophic brain injury, the diagnosis of brain death can be confirmed by a clinical neurological examination. In considering the diagnosis 'brain death', the most important criterion is that the cause of the brain damage is established. If the cause is insufficiently, the presence of brain death should be seriously doubted, unless an isoelectric EEG is observed.

[Hypertensive encephalopathy: does not only occur at high blood pressure]. / Hypertensieve encefalopathie: niet alleen bij zeer hoge bloeddrukwaarden.

A 45-year-old man presented with severe hypertension, headache, cortical blindness, and a depressed level of consciousness. A second patient, a 33-year-old woman, was admitted with pre-eclampsia. She developed lethargy, headache, bilateral extensor plantar responses, and seizures. The third patient, a 62-year-old man, presented with acute renal failure due to necrotising vasculitis and glomerulonephritis. Five days after treatment with immunosuppressive drugs had been initiated, he developed headache, confusion, seizures, and cortical blindness. Hypertensive encephalopathy is characterised by headache, vomiting, disturbances in cognition and level of consciousness, visual abnormalities, and seizures. Imaging studies often demonstrate oedema of the white matter in the posterior parietal and occipital areas of the brain. This so-called reversible posterior leucoencephalopathy syndrome is well known in patients with severe hypertension, but it is also associated with immunosuppressive drug use and renal failure. It can be recognised by its fairly characteristic clinical features (different combinations of headache, vomiting, changes in cognition and level of consciousness, seizures, muscle weakness, and visual symptoms) and by its specific imaging findings. Treatment consists of reducing the blood pressure and reducing or discontinuing the use of immunosuppressive drugs. If the treatment is started promptly, symptoms and imaging abnormalities are usually reversible.

[Referral of patients with polyneuropathy by the family physician: influence of type of symptoms but not of age]. / Verwijzing van patiënten met een polyneuropathie door de huisarts: geen invloed van de leeftijd, maar wel van de aard van de klachten.

OBJECTIVE: To investigate the influence of the age of the patient and the nature of a polyneuropathy on the referral behaviour of general practitioners (GPs). DESIGN: Written questionnaire sent to GPs regarding paper case records of polyneuropathy. SETTING: University Hospital Utrecht, the Netherlands. METHODS: 1590 GPs were asked about their differential diagnosis regarding a paper case record of a patient with polyneuropathy. There were six case records, differing in age (53, 64 and 73 years) and nature of the disease (sensory or sensorimotor polyneuropathy). The GPs were divided into six groups with similar demographic characteristics and type of practice. To avoid focus on polyneuropathy, all GPs also received questions about three other neurological cases (amaurosis fugax, radicular syndrome and vasovagal collapse). RESULTS: The mean response of the questionnaire was 54% (n = 844). Most GPs diagnosed the polyneuropathy (analysis of variance; p < 0.0001). The age of the patient did not influence the diagnosis nor the referral behaviour. At least 73% of the patients with a sensory and 81% of the patients with a sensorimotor polyneuropathy were referred to neurologists for further investigations (chi(2)-test; p < 0.05). CONCLUSION: At least 73% of the GPs referred a patient with polyneuropathy to a neurologist; patients with muscle weakness were referred more often than patients with only sensory disturbances. Referral was not influenced by the age of the patient.

Glucose levels and outcome after subarachnoid hemorrhage.

In a cohort of 337 patients with subarachnoid hemorrhage (SAH), we investigated the relationship between blood glucose levels, baseline characteristics, and outcome by means of Student's t-test and multivariate logistic regression. The mean glucose levels on admission and from day 1 to 10 were significantly higher in patients with poor condition on admission and in patients with poor outcome. In a multivariate analysis, glucose level on admission was not an independent predictor of outcome. Hyperglycemia may be a link in the association between poor condition on admission and poor outcome.

A new variant of sensory ataxic neuropathy with autosomal dominant inheritance.

We describe a Dutch family with sensory ataxia in two generations, late onset of symptoms (over the age of 40 years) and slow progression. Clinical, electrophysiological and sural nerve biopsy findings revealed a sensory polyneuropathy due to axonal degeneration of myelinated nerve fibres in four of five investigated siblings. Other neurological abnormalities in the affected family members consisted only of mild eye movement disturbances, probably due to cerebellar involvement. Five other family members were investigated and found unaffected. As the disease is inherited from the affected father to his sons and daughters, this is the first description of a probably autosomal dominant form of late onset hereditary sensory neuropathy with predominant sensory ataxia and minor other neurological abnormalities.

Sjögren's syndrome in patients with chronic idiopathic axonal polyneuropathy.

OBJECTIVE: To assess the presence of symptoms and signs of Sjögren's syndrome in patients with otherwise idiopathic axonal polyneuropathy and to develop guidelines for the diagnostic approach with respect to Sjögren's syndrome in these patients. METHODS: Sixty five patients with axonal polyneuropathy in whom an aetiological diagnosis could not be made underwent (1) a standard interview focusing on ocular and oral sicca symptoms, (2) physical examination, (3) tests for objective assessment of keratoconjunctivitis sicca, (4) extensive serological investigations, and (5) a sublabial salivary gland biopsy. RESULTS: In forty nine patients a sublabial salivary gland (SSG) biopsy was performed, thereby completing the whole investigation for Sjögren's syndrome. Three of these 49 patients (all women) had an SSG biopsy specimen suggestive of Sjögren's syndrome, which, in combination with other symptoms and signs, led to a diagnosis of primary Sjögren's syndrome. CONCLUSIONS: None of the three patients with primary Sjögren's syndrome had spontaneously complained about sicca symptoms and the clinical neurological picture of them did not differ from the other patients in the study. Therefore, in patients with chronic idiopathic axonal polyneuropathy, especially in women, a systematic investigation for Sjögren's syndrome should be done, because the presence of Sjögren's syndrome may have implications for treatment and justifies a clinical follow up on a regular base.

Measuring ataxia: quantification based on the standard neurological examination.

To quantify ataxia in a simple way four tests were developed and analysed, based on the neurological examination: a tapping test for the arms (test 1), another one for the legs (test 2), a quantified finger-to-nose test (test 3), and a modified Romberg test (test 4). All tests were performed by 115 volunteers, 13 patients with cerebellar ataxia and 25 patients with sensory ataxia due to neuropathy. The test-retest repeatability was excellent. Tests 1, 2 and 4 were age-dependent, with lower scores above age 65. On test 1, 2 and 4 both groups of patients performed worse than controls; the correlation with the ataxia scale of Nobile-Orazio and the modified disability Rankin scale was good (P < 0.05). Although test 3 could differentiate between sensory and cerebellar ataxia, it was not useful for quantifying the degree of ataxia. To determine the practical value of the four tests, 11 patients performed the tests for a second time after a follow up period of 16 months. The results indicate that tests 1, 2 and 4 are sensitive for the detection of ataxia and of changes in its severity.