Plaques, symptoms, and the remitting course of multiple sclerosis

Serotonergic neuronal sprouting as a potential mechanism of recovery in multiple sclerosis

Experimental allergic encephalomyelitis (EAE) is widely considered as an animal model of multiple sclerosis (MS). Damage to the bulbospinal serotonergic (5-HT) neurons occurs in the early paralytic stages of EAE in rats with the severity of neurologic signs corresponding to spinal serotonergic depletion. Neurologic recovery of EAE rats is associated with reestablishment of spinal 5-HT transmission possibly through sprouting of undamaged axons and nerve terminals. Damage to the bulbospinal serotonergic fibers also occurs in patients with MS (as reflected by reduced lumbar CSF 5-HIAA levels) and may contribute to several manifestations of the disease including autonomic dysregulation, sensory symptoms (i.e., paresthesias, pain) and motor symptoms (weakness, spasticity, clonus). Spinal serotonergic neuronal sprouting with regeneration of 5-HT nerve terminals may also occur in the early stages of MS and may be associated with spontaneous remission of MS symptoms following an acute relapse. Sprouting of serotonergic neurons may also explain the disparity in MS between the extent of demyelinating plaques and clinical signs of the disease. The chronic course of MS may be associated with progressive axonal degenerative changes with reduction of serotonergic nerve terminals and loss of their sprouting capability. It is proposed that the beneficial effects of treatment with AC pulsed electromagnetic fields on the symptoms and course of the disease in patients with chronic progressive MS may be related in part to renewed sprouting of serotonergic neurons.

Lack of a correlation between demyelinating plaques on MRI scan and clinical recovery in multiple sclerosis by treatment with electromagnetic fields

A 50 year-old woman presented in January of 1995 with a prolonged history of symptoms of multiple sclerosis (MS) and was classified at the time with a remitting-progressive course. Her chief symptoms included slurring of speech, impairment of vision with intermittent diplopia, difficulties with gait and balance with spastic-ataxic gait, mental depression, insomnia, fatigue, impaired cognitive functions notably poor short term memory and recurrent urinary tract and sinus infections. An MRI scan showed multiple nodular demyelinating lesions scattered in the subcortical white matter and periventricularly of both cerebral hemispheres. Over the following 18 months, while receiving three treatment sessions per week with picotesla electro-magnetic fields (EMFs) which were applied extracranially, she showed a significant recovery in both physical and mental symptoms and additionally experienced decreased susceptibility to infections. In addition, the course of her disease appeared to have stabilized as opposed to the preceding 5 years during which time she experienced insidious, steady deterioration in her functioning. Despite this remarkable clinical recovery through the application of EMFs, and MRI scan obtained at the same diagnostic center 18 months after initiation of treatment with EMFs showed no changes in the number and size of the demyelinating plaques. These findings demonstrate lack of a correlation between recovery of symptoms and the number and extent of demyelinating plaques on MRI scan. It has been known since the days of Charcot in the latter half of the 19th century that in MS there is a great disparity between the histopathological changes of the disease and neurologic deficits. This report enhances the notion that demyelination may reflect an epiphenomenon of the disease.

Reversal of an acute parkinsonian syndrome associated with multiple sclerosis by application of weak electromagnetic fields

The occurrence of movement disorders and particularly Parkinsonian symptoms is uncommon in patients with multiple sclerosis (MS) despite the rather frequent presence of demyelinating plaques in the basal ganglia. This disparity between the occurrence of clinical symptoms in MS and the distribution of demyelinating plaques suggests that impairment of neurotransmitter functions rather than demyelination may be critical to the clinical manifestations of the disease. A 48 year old woman with remitting-progressive MS developed a bilateral Parkinsonian syndrome in association with acute emotional stress which resolved after she received two brief successive extracerebral applications of low frequency picotesla flux density electromagnetic fields (EMFs). It is believed that in this patient Parkinsonism may have existed in a subclinical form and that acute stress, which previously has been shown to precipitate symptoms of Parkinson's disease, triggered the onset of Parkinsonism by further reducing dopaminergic and serotonergic neurotransmission in the basal ganglia. The rapid reversal of the Parkinsonian syndrome by EMFs was related to a presumed augmentation of dopaminergic and serotonergic neurotransmission which, on the basis of CSF studies, is reduced in chronic MS patients. The efficacy of EMFs in the treatment of Parkinson's disease had been documented previously but this report demonstrates that this treatment modality is beneficial also for the treatment of Parkinsonism developing in the setting of other neurodegenerative disorders.

Magnetisation transfer ratios and transverse magnetisation decay curves in optic neuritis: correlation with clinical findings and electrophysiology

Conventional MRI sequences do not permit the distinction between the different pathological characteristics (oedema, demyelination, gliosis, axonal loss) of the multiple sclerosis plaque. Magnetisation transfer imaging and transverse magnetisation decay curve (tMDC) analysis may be more specific. These techniques have been applied to the optic nerves in 20 patients with optic neuritis and the results correlated with clinical and visual evoked potential (VEP) findings. tMDC analysis failed to identify separate intracellular and extracellular water compartments within the optic nerve but gave a measure of transverse relaxation time (T2) without the confounding effects of CSF in the nerve sheath. Both T2 and magnetisation transfer ratio (MTR) were abnormal after an episode of optic neuritis. T2 did not correlate with visual function or with VEP latency or amplitude. There was a significant correlation between MTR reduction and prolongation of VEP latency: this increased latency may reflect an effect of myelin loss on MTR. Longer lesions were associated with worse visual outcome, implying that the overall extent of pathological involvement is likely to influence the degree of functional deficit.

Chronic relapsing multiple sclerosis: a case of rapid recovery by application of weak electromagnetic fields

A 54 year-old woman was diagnosed with multiple sclerosis (MS) in 1985 at the age of 45 after she developed diplopia, slurred speech, and weakness in the right leg. A Magnetic Resonance Imaging (MRI) scan obtained in 1985 showed several areas of plaque formation distributed in the periventricular white matter and centrum semiovale bilaterally. Coincident with slow deterioration in her condition since 1990 a second MRI scan was obtained in 1991 which showed a considerable increase in the number and size of plaques throughout both cerebral hemispheres, subcortical white matter, periventricularly and brainstem. In 1994, the patient received treatment with Interferon beta- 1b (Betaseron) for 6 months with no improvement in symptoms. However, following two successive extracranial applications of pulsed electromagnetic fields (EMFs) in the picotesla (pT) range each of 20 minutes duration the patient experienced an immediate improvement in symptoms most dramatically in gait, balance, speech, level of energy, swallowing, mood, and vision. On a maintenance program of 3 treatments per month the patient's only symptom is mild right foot and leg weakness. The report points to the unique efficacy of externally applied pT range EMFs in the symptomatic treatment of MS, indicates a lack of an association between the extent of demyelinating plaques on MRI scan and rate and extent of recovery in response to EMFs, and supports the notion that dysfunction of synaptic conductivity due to neurotransmitter deficiency particularly of serotonin (5-HT) contributes more significantly to the development of MS symptoms than the process of demyelination which clinically seems to represent an epiphenomenon of the disease.

Correlation of clinical features and findings on cranial magnetic resonance imaging with urinary myelin basic protein-like material in patients with multiple sclerosis

Immunoreactive material that appears to be a peptide encompassing all or a portion of residues 80 to 89 of myelin basic protein is present in normal unconcentrated urine and is increased in certain patients with multiple sclerosis (MS). Compared with normal controls, urines collected randomly from 158 MS patients or in a clinical research unit from 8 patients with MS had higher mean values of urinary MBP-like material (MBPLM). The level of MBPLM in urine showed no direct relationship to MBPLM in cerebrospinal fluid and did not correlate with clinical relapses of disease. In the other neurological disease control group (26 patients), some patients with other inflammatory diseases, but not stroke or early phase Guillain-Barré syndrome, also showed elevations. Among the subtypes of MS, those with secondary chronic progressive disease had the highest values. Urinary MBPLM showed no definite correlation with or effect of treatment with glucocorticoids and immunosuppressants except that a lower level of urinary MBPLM showed a weak relationship with improvement following treatment with methylprednisolone/prednisone. In a serial study of 8 patients with unenhanced cranial magnetic resonance imaging and 20 patients with gadolinium-enhanced cranial magnetic resonance imaging, urinary MBPLM did not show a direct correlation with new or enhancing lesions. Urinary MBPLM does not parallel acute myelin damage but appears to reflect an ongoing process, possibly linked to attempted efforts at remyelination.

Resolution of longstanding symptoms of multiple sclerosis by application of picoTesla range magnetic fields

Recent clinical reports have suggested that treatment with extremely weak magnetic fields (MF) in the picoTesla range is an efficacious modality for the symptomatic therapy in patients with multiple sclerosis (MS) during the remission and exacerbation periods of the disease. The present communication concerns a 64 year old woman with a 22 year history of MS of the chronic-progressive type who presented with a longstanding history of ataxia of gait, weakness in the legs, difficulties with swallowing, loss of bladder control, blurred vision, diplopia, chronic fatigue, and cognitive impairment. In this patient two 30 minute treatments with MF on two separate days resulted in a dramatic improvement of symptoms. Specifically, the patient experienced marked improvement in balance and gait as well as increased strength in the legs to the extent that she was able to abandon the use of a walker within 48 hours after initiation of magnetic treatment. In addition, there was complete resolution of diplopia, bladder dysfunction, and fatigue with improvement in mood and cognitive functions. The report attests to the unique efficacy of extremely weak MF in the symptomatic treatment of patients with MS including those patients with a chronic progressive course of the disease and supports the hypothesis that dysfunction of synaptic conductivity due to neurotransmitter deficiency specifically of serotonin rather than demyelination underlies the neurologic deficits of the disease.

Emotional stress and coping in multiple sclerosis (MS) exacerbations

Ninety-five pairs of MS patients in exacerbation and remission were compared on emotional stress in the previous three months. Patients in exacerbation scored higher on emotional disturbance and intensity of stressful events than patients in remission, but lower on frequency of compensating uplifts. There was also a tendency for more patients in exacerbation than remission to favour emotion-focused coping techniques over problem-solving or social support. Whether patients building to an exacerbation over-react to various events or unresolved emotional stress precipitates exacerbations, MS patients might benefit from counselling in stress reduction techniques.

Paroxysmal facial pain in disseminated sclerosis treated by retrogasserian glycerol injection

In the material of patients with trigeminal neuralgia treated by retrogasserian glycerol injection at the Karolinska Hospital, 23 cases (8%) were also diagnosed as suffering from disseminated sclerosis. These patients were often on carbamazepine treatment before the procedure, a regimen known to cause severe side effects and increase pre-existing symptoms in patients with multiple sclerosis. Following glycerol injection, more than 90% became pain-free within the first 2 months and 82% could discontinue drug therapy. This initial outcome corresponds well to the results in our larger series, but the long-term results in the group with multiple sclerosis is less satisfactory, with 61% recurrence at follow-up 8-79 months following treatment. In total 48% were pain-free at follow-up, following reinjections in 8 cases. In spite of less satisfactory long-term results, more than three-fourths of the patients wanted another glycerol injection after only low-dose trial with carbamazepine in case of recurrence.

Multiple sclerosis: failure of treatment with verapamil in a pilot trial

Verapamil hydrochloride, a lipophilic calcium channel blocking agent was used in the treatment of 11 patients with multiple sclerosis. The rationale of the therapy was to improve the conduction capacity of the damaged nerve fibres. The therapy did not prove effective in a pilot trial.

Pathogenesis of multiple sclerosis. A critical reappraisal

The pathogenesis of multiple sclerosis remains a dilemma despite many years of study. Evidence for an infective agent is lacking: much doubt remains regarding the pathogenetic significance, if any, of the many reported alterations of the immune system. On the other hand, the well-documented facts that multiple sclerosis plaques are invariably located around blood vessels and that alterations of the blood-brain barrier permeability are always present in the plaque suggest that these old observations should be reconsidered. There is strong evidence to support the idea that the alteration of the blood-brain barrier is an obligatory step in the development of the plaque. It may result from a variety of environmental factors among which must be mentioned trauma to the nervous system, as well as the immunological changes resulting from viral infections and vaccinations. The available data lead to the following hypothesis: multiple sclerosis is a disease which requires the following factors for the production of demyelinating lesions of the central nervous system: a genetically determined susceptibility, an environmental, probably viral, probably immune-mediated initiatory event producing a symptomless systemic illness, a subsequent alteration of the blood-brain barrier resulting from diverse mechanisms including trauma or a second, immune-mediated event, a myelinoclastic plaque-forming mechanism which is operative only in the central nervous system.

Evoked potential testing in relatives of multiple sclerosis patients

Evoked potential (EP) tests were obtained in 110 neurologically normal first-degree relatives of patients with multiple sclerosis. Visual EP tests were performed in all relatives; brainstem auditory and median nerve somatosensory EP tests were performed in 67 relatives. The relatives had a mean visual EP P100 latency that was significantly longer than that for normal subjects controlled for age and gender. Asymmetries were seen in results from individual MS relatives, including interocular visual EP P100 differences of up to 14 ms, and interarm somatosensory Erb-N18 differences of up to 3.0 ms. We identified 19 pairs of patients and relatives who were HLA identical and 18 other pairs who were HLA double nonmatched. EP asymmetries were seen more often in the HLA identical siblings than in the HLA double patients, especially if they share HLA types with the patients. Since less than 2% of siblings of MS patients would be expected to eventually develop clinical MS, these small subclinical electrophysiological changes are not expected to be a sign of the future appearance of clinical MS. Clinicians should be aware not to overinterpret small EP changes in relatives of MS patients.

Indicators of disease activity in multiple sclerosis. Studies of myelin basic protein-like materials

Defining the immunochemical basis for the detection of BP peptides in body fluids has led to an appreciation of the complexity of the number and location of epitopes in BP peptide 43-88. There appear to be roles for epitopes based on both sequence and conformation of these small peptides. Antisera to some of the fragments of BP peptide 43-88 may have restricted reactivity with BP peptide 43-88 and BP. The amount of BP-like material that enters CSF and cross-reacts with BP peptide 43-88 is related to the recognition of an epitope or epitopes in the C-terminal portion of this peptide. The immunochemical detection of BP peptides in body fluids is dependent on the precise identification of the BP peptides present.

Immunoregulatory T-cells and lymphocytotoxic antibodies in active multiple sclerosis: weekly analysis over a six-month period

Immunoregulatory T-cell subsets were measured at weekly intervals over a 4 to 6 month period using monoclonal antibodies (anti-T4 = inducer cell; anti-T8 = suppressor/cytotoxic cell) in a group of 6 patients with multiple sclerosis (MS) and in 4 age- and sex-matched controls. Decreases in the T8 subset and increases in the T4:T8 ratio were present in 4 of the patients with MS but not in controls. Two patients who were neurologically stable during the study period had no changes in the T4:T8 ratio; 2 patients with intermediate disease activity of the relapsing-remitting type had elevated ratios on 3 and 4 occasions respectively; the patient with the most clinically active MS had an abnormal ratio 12 of 27 times. One patient with chronic-progressive MS had an elevated ratio on each occasion tested. No abnormalities in T-cell subsets were present in any of the controls. On three occasions an elevated T4:T8 ratio appeared to precede an acute relapse by 1.5 to 7 days. Lymphocytotoxic antibodies (LCA) against whole lymphocytes or against isolated T-cell subsets were measured in these patients and in a larger group of MS patients, and were not found to correlate with changes in T-cell subsets. This report extends previous findings linking changes in T-cell subsets to disease activity in patients with MS.

Diagnostic techniques in multiple sclerosis

Although multiple sclerosis (MS) has been an area of great interest and effort in numerous scientific disciplines, its etiology, pathogenesis and therapy remain mysterious. Perhaps the most significant advances have resulted from the ability to be more precise in establishing the diagnosis of MS. Among the most important of the new diagnostic tools are electrophysiological techniques for examination of the visual and oculomotor systems. Tests such as the visually evoked potential (VEP) can confirm the existence of clinically suspected lesions and document the presence of asymptomatic ones. Various electrophysiological techniques for detection and evaluation of MS, as well as CSF analysis, psychological and neuroradiological procedures, and immunological observations are described. The relationship between optic neuritis and MS is reviewed, as are therapeutic regimens in use and under study.

Some recent advances in the clinical aspects of multiple sclerosis

Recent work on the clinical aspects of multiple sclerosis is reviewed with particular regard to symptomatology: New approaches to clinical symptoms and the identification of more subtle impairments are illustrated by recent studies of visual function in M.S. patients; pathophysiology: It is now widely appreciated that the dysfunction observed in patients is not determined solely by histologically demonstrable demyelination. The function of the demyelinated neuron is highly variable, being dependent upon factors which may change from day to day. Recent ideas about 'neuro-electric blocking factors' and other factors that may influence demyelinated neurons and hence symptoms are discussed; diagnosis: tests on C.S.F., electro-physiological and psychophysiological tests and computer tomography as aids to diagnosis and the controversy over 'specific' blood tests are reviewed; course and prognosis: Long term follow-up studies confirm that, in a significant proportion of cases, the course of M.S. may be benign and have identified some early prognostic indices;

TREATMENT

The results of trials of symptomatic (spinal cord stimulation) and would-be curative therapies (such as dietary supplementation with poly-unsaturated fatty acids and immunosuppression) are briefly discussed.

The internodal axon membrane: electrical excitability and continuous conduction in segmental demyelination

1. Longitudinal action currents were recorded from single undissected myelinated nerve fibres in intact, perfused ventral roots of normal rats and ones treated with diphtheria toxin to produce demyelination. 2. Closely spaced recording electrodes (120 micron), signal averaging and the use of a calibrating current throught the root permitted membrane currents to be determined over 240 micron lengths of nerve. Contour plotting was used to plot membrane current density as a function of space and time. 3. The previous result of Rasminsky & Sears (1972) of delayed saltation in demyelinated nerve fibres was confirmed. 4. In addition a new phenomenon of continuous conduction was observed, along distances of up to 1 1/2 times the afferent internodal distance. The continuous spatial distribution of inward current in these cases showed that electrical excitability was distributed along the internodes. 5. Internodal excitability was also revealed in demyelinated fibres by extra foci of inward current judged to be internodal on the basis of the spacing of the other (nodal) foci. 6. Continuous conduction occurred at velocities in the range of 1.1-2.3 m/sec or roughly 1/20th-1/40th of the velocities expected for normal stretches of the same fibres. 7. The continuous conduction was attributed to conduction along lengths of demyelinated axon. This was supported by estimates of 0.86 and 1.5 muF/cm2 for membrane capacity from the foot of a continuously conducted action potential. 8. The implications of internodal electrical excitability in demyelinated nerve fibres are discussed in relation to (a) recent estimates of the density of sodium channels in intact and homogenized normal nerves, (b) the pathophysiology of demyelinating disease.

Conduction through demyelinated plaques in multiple sclerosis: computer simulations of facilitation by short internodes

Clinical and laboratory observations both suggest that it may be possible for action potentials to traverse, in a continuous manner and without interruption, demyelinated zones along some axons. This continuous mode of conduction requires the presence of sufficient numbers of sodium channels in the demyelinated region. One of the factors which will tend to prevent such conduction is the impedance mismatch at sites of focal demyelination, which may result in a reduction in current density sufficient to cause conduction failure. As part of an effort to examine the conditions which would promote conduction into, and beyond, the demyelinated region, we examined, using computer simulations, the effects of reduction in length of the proximal internodes closest to the demyelinated region. Our results indicate that reduction in length of the two internodes closest to the demyelinated region. to approximately one-third of normal length or less, will facilitate conduction beyond the plaque. The results suggest that reductions in internode length, which have been histologically observed along some demyelinated fibres, may have functional significance in terms of facilitating conduction past focally demyelinated zones.

The benign form of multiple sclerosis. Anatomo-clinical aspects

The present paper is a study of three cases presenting the pathological aspect of chronic, non-evolutive multiple sclerosis, corresponding to a clinical picture of benign multiple sclerosis. The first case was discovered at autopsy, the second patient had two subclinical attacks of multiple sclerosis, with a twenty-year evolution (forme fruste), and in the third case the course of the chronic multiple sclerosis ran parallel to that of a cerebral and visceral arteriopathy. Anatomic study of the demyelinating lesions revealed their non-evolutive aspect and the presence within the plaques of lesions of the walls of small vessels with the perivascular adventitial fibrosis. The vascular changes appear to play a primordial role in the lack of evolution of the demyelinating areas, manifested clinically by a stationary, benign picture.

Multiple sclerosis. A clinical and theoretical review

✓ The author presents a review of multiple sclerosis, and summarizes the present knowledge of the disease in relation to cause, pathogenesis, pathophysiology, and treatment. He stresses the inconsistency between the central nervous system pathology and the occurrence of signs and symptoms.

A computer simulation of conduction in demyelinated nerve fibres

1. The theoretical effects of demyelination on conduction of a propagated impulse have been examined in a computer simulated myelinated nerve fibre. Demyelination was simulated by increasing the capacitance and conductance of the myelin sheath of individual internodes or parts of internodes.2. Internodal conduction time increased as myelin thickness was decreased. The increase in internodal conduction time became more precipitous as the myelin became thinner. Propagation continued past a single demyelinated internode until myelin thickness was uniformly reduced to less than 2.7% of normal myelin thickness.3. Paranodal demyelination was more effective in slowing impulse conduction than was uniform demyelination of an entire internode with an equivalent rise in overall internodal capacitance and conductance.4. The effects on conduction of demyelination of two adjacent internodes or of two internodes separated by a normal internode were more than the sum of the effects of demyelination of each internode individually.5. Propagation across a severely demyelinated internode was blocked with an increase in internal sodium concentration which had a trivial effect on conduction in a normal fibre.6. Propagation across a severely demyelinated internode was blocked with increased temperature at a temperature at which propagation proceeds normally across normal internodes.7. The similarity between the findings of the computer simulations and the experimental findings in demyelinated fibres is discussed.

Multiple sclerosis associated with defects in neuromuscular transmission

Three patients with multiple sclerosis characterized by exacerbations and remissions of nervous system signs and symptoms disseminated in time and space also had the kind of easy fatiguability seen in myasthenia gravis. In each case abnormal decrements to repetitive stimulation were electromyographically demonstrated and treatment with ephedrine or anticholinesterase drugs increased the patient's functional capacity while improving the electromyographic abnormality. The suggestion is that these patients represent an overlap syndrome, analogous to the overlap syndrome existing between systemic lupus erythematosus and rheumatoid arthritis where clinical and laboratory features of two diseases coexist in the same patient at the same time. Presumably some patients with multiple sclerosis have deficient production of acetylcholine, just like patients with myasthenia, and treatment with agents useful in myasthenia is able partially to correct the symptoms caused by the deficiency. The cases illustrate how in neurology greater attention to the more immediate cause of clinical symptoms, in the absence of a known aetiology, may result in benefit to the patients.