Familial hyperkalemic periodic paralysis and bipolar disorder: a linkage and treatment study.

Familial hyperkalemic periodic paralysis and bipolar disorder are both hereditary disorders, characterized by episodes of illness separated by periods of remission, and possibly related to abnormalities in cellular ion transport. Recently we discovered a patient who suffered from both illnesses, as did his mother and grandmother. However, a detailed investigation of the pedigree suggested that these two disorders are not linked genetically. Furthermore, a placebo-controlled double-blind trial of lithium carbonate in this patient found lithium ineffective in preventing the attacks of paralysis, in contrast to another recent study which found lithium effective in hypermagnesemic periodic paralysis.

Genetic analysis of multiple sclerosis in Shetland.

In a family study of all patients with multiple sclerosis in Shetland the number of inbred patients, although high for Britain and higher than in Orkney, is not higher than the number among controls, and the inbreeding coefficients suggest that there is no recessive involvement of rare genes in the aetiology. The kinship coefficients show close interweaving of ancestries of patients and controls and eliminate from the aetiology any involvement of recently introduced single genes dominant or codominant in effect. Family histories show that single locus inheritance is unlikely. Any genetic involvement is likely to be polygenic, but on a multifactorial hypothesis the estimates of heritability are very low. The findings suggest that the genetic contribution to the aetiology of the disease in Shetland is slight.

The etiology of multiple sclerosis: temporal-spatial clustering indicating two environmental exposures before onset.

Studies in the Orkney and Shetland Islands have demonstrated the highest rates of multiple sclerosis (MS) recorded. Accumulated evidence suggests that an environmental factor is paramount in etiology. The role of an environmental exposure (infectious or toxic) is confirmed in this study by the demonstration in Orkney of clustering of cases in time and space. Lifetime data showed temporal-spatial clustering of MS patients (1) at least 21 years prior to onset, and (2) just prior to onset. Each of the two time clusters occurred on three separate islands. No clustering was seen at birth, by chronological age, or by schooling. Clustering was not demonstrated in Shetland. Previous efforts to demonstrate clustering may have failed because of lack of specificity of the data or inappropriate methodology. These data indicate that not one but two environmental factors play a role in the etiology of MS, representing exposures to two different environmental insults, or exposure twice to the same insult, prior to onset of MS.

Multiple sclerosis in the Orkney and Shetland Islands. III: Histocompatibility determinants.

Histocompatibility testing was performed in 48 multiple sclerosis patients and two carefully matched control groups in Orkney Islands, an area of high multiple sclerosis prevalence. The frequency of HLA-A3, HLA-B7, and DW2 was comparable in patients and controls. However, HLA-B7 was significantly more common in female patients compared with male patients. A B-cell alloantigen (B-cell 4) was also as frequent in patients as among controls. Strong linkage between HLA-B7, DW2 and B-cell 4 occurred in controls, but not patients; the linkage was particularly striking in female controls. These data are not consistent with theories that relate certain of the histocompatibility antigens to the aetiology of multiple sclerosis.

Multiple sclerosis in the Orkney and Shetland Islands. I: Epidemiology, clinical factors, and methodology.

An epidemiological and clinical study of multiple sclerosis (MS) in the Orkney and Shetland Islands showed that the prevalence rate of the disease is the highest in the world (309 and 184/100 000, respectively). The clinical entity, MS, is similar to that found in other parts of the world, except that optic neuritis not followed by MS is rare. Analysis of death certificates indicated that MS has probably occurred at the same rate in these islands for nearly a century. Although the incidence of MS is high, the incidence rate has remained constant over time. A rapidly increasing prevalence of MS has occurred in Orkney, with a more modest increase in Shetland, over the past 20 years, which is largely due to an increase in survival. Demographic factors, case ascertainment, and emigration have contributed little to the increasing prevalence of MS in these islands.

Multiple sclerosis in the Orkney and Shetland Islands. II: The search for an exogenous aetiology.

In Orkney and Shetland, a survey of lifetime events was undertaken in multiple sclerosis patients and two control groups to define shared exposure to an exogenous agent or environmental insult. Analyses of demographic factors, diet, social class and occupation, housing and environment, animal exposure, schooling, travel, infectious disease, and medical history disclosed a remarkable similarity in responses between patients and controls for a majority of questions. However, differences were noted for sanitation, place of residence at onset, and animal exposure. The data give additional support for an exogenous aetiology of multiple sclerosis.

Multiple sclerosis in the Orkney and Shetland Islands. IV: Viral antibody titres and viral infections.

A controlled serologic survey of antibody titres to 17 viruses was undertaken in multiple sclerosis patients in the Orkney and Shetland Islands. No consistent pattern of elevated antibody titre levels or the presence of antibody was noted in patients compared with two control groups. Because of the isolation of these islands, the mean age at acquisition of common childhood infections, including measles, was considerably older than that of inhabitants of Europe and the United States of America. The age of occurrence of varicella was consistently younger in patients than in controls. Of note is the fact that six patients had measles after the onset of MS. This study failed to incriminate any of the viruses tested in the aetiology of MS.

Multiple sclerosis in the Orkney and Shetland Islands. V: The effect on viral titres of histocompatibility determinants.

HLA phenotypes were correlated with serum antibody titres to eight viruses in patients with multiple sclerosis and two matched control groups in the Orkney Islands. In patients, no specific HLA antigen was associated wtih increased or decreased viral titres. However, HLA-B7 was significantly correlated with higher measles titres in healthy controls. Furthermore, controls who had the HLA haplotypes, B7, DW2 ad B-cell 4, demonstrated significantly higher antibody titres to measles and rubella than controls without these determinants (P less than 0.005). To determine the effect of age, sex, and other variables upon viral titres, regression analysis was undertaken. A significant proportion of measles titre variance in patients was explained by sex and clinical factors. Among normal controls, HLA determinants explained a significant amount of measles and rubella titre variance. These data suggest that viral titres in normal individuals are influenced by certain HLA antigens and give indirect evidence that another, as yet undefined, determinant in the histocompatibility complex governs the immune response.

Polymorphisms and multiple sclerosis in Orkney.

Study of the blood group, isoenzyme, and serum protein systems representing polymorphic variants at 23 loci, in a population of 53 multiple sclerosis patients in Orkney, their relatives, and control series, showed that patients were neither morre homozygous nor more inbred than controls. Any possible association of the disorder with the ABO and rhesus blood groups was not directly causal, but was related to the families of the patients rather than to the patients themselves.

Genetic analysis of multiple sclerosis in Orkney.

In a family study of all patients with multiple sclerosis (MS) in Orkney, the number of inbred among patients, although high for Britain, is not higher than the number among controls, and the inbreeding coefficients appear to eliminate recessive involvement of rare genes from the aetiology. The kinship coefficients show that the ancestries of patients and controls are closely enmeshed, and eliminate from the aetiology involvement of recently introduced genes dominant or codominant in effect. Family histories show that single locus inheritance is unlikely unless penetrance is very low. Multifactorial genetic involvement is much more likely, and it is compatible with all recent findings; on this hypothesis heritability estimates, not altogether satisfactory because of the limited number of patients in the population, suggest that the genetic contribution to the aetiology of the disease in Orkney is only moderate.

Lithium prophylaxis of corticotropin-induced psychosis.

Corticotropin is one of the few accepted treatments for acute exacerbations of multiple sclerosis and retrobulbar neuritis. Psychosis is a serious side effect usually necessitating discontinuation of the drug therapy. Because mood disorders preponderated in most patients previously described with this psychosis, 27 patients were empirically treated with lithium carbonate concurrently with corticotropin. In none of the patients treated with lithium did a psychotic reaction occur, although in a comparable group of 44 patients previously treated identically with corticotropin but without lithium, six (14%) became psychotic.

Cooperative study of hospital frequency and character of transient ischemic attacks. VIII. Risk factors.

A total of 969 (73%) of 1,328 patients with cases of suspected transient ischemic attacks (TIAs) who came to six institutions during a 21-month period were followed up. Factors were identified and prospectively analyzed for risk for further TIAs, stroke, and deatn. A history of multiple carotid artery TIAs was significantly related to further TIAs. A single TIA placed the patient at greater risk for early infarction. Older age, male sex, and unreliability to take dangerous medication were risk factors for cerebral infarction. Anticoagulant therapy, older age, male sex, diabetes mellitus, heart disease, abnormal ECG, and poor surgical risk were factors for death. The increased mortality associated with anticoagulants was confined to the older age group. While white patients treated with antiplatelet-aggregating agents had a lower mortality than those treated otherwise, this was not true amont black patients.

The prognosis of acute and subacute transverse myelopathy based on early signs and symptoms.

Fifty-two patients with acute and subacute transverse myelopathy (TM) were evaluated at the Massachusetts General Hospital between 1955 and 1975 and followed for 1 to 23 years (average, 5). Nineteen had symptoms of a recent acute infectious illness, 3 had cancer, and 1 had undergone a recent operation. There were four types of initial symptom. Twenty-four patients had paresthesias at the onset of the illness, 18 had pain, usually interscapular, 7 had leg weakness, and 3 had urine retention. Prognosis depended on the nature of the onset of TM. An acute catastrophic onset was generally associated with back pain and led to a poor outcome in 7 and a good outcome in only 1 of 11 patients. A subacute progressive onset over several days to four weeks, generally with ascending paresthesias or leg weakness, was associated with a good outcome in 15 and fair outcome in 17 of 37 patients. Preceding febrile illness, treatment with corticosteroids, and the nature of CSF abnormalities had no effect on outcome. Multiple sclerosis evolved in 7 patients during the follow-up period. Because of the frequency with which mass lesions were missed, the need for myelography in the diagnosis of TM is emphasized. The distinguishing clinical characteristics of TM provide guidelines for diagnosis and prognosis.

Cooperative study of hospital frequency and character of transient ischemic attacks.

Information was collected among six participating medial centers on frequency of performance and the percentage of abnormality of 30 tests performed on patients with complaints suggesting transient ischemic attacks (TIAs). A number of these were commonly performed and commonly exhibited abnormalities. Although the diagnosis of TIA is made by history and physical examination, these tests were of value in aiding the physician to determine possible causes of TIA, to detect risk factors of associated conditions, to rule out alternative diagnoses, and to assess the patient's ability to tolerate different types of therapy.

Cooperative study of hospital frequency and character of transient ischemic attacks. VI. Patients examined during an attack.

Examination during an episode of transient ischemic attack (TIA) was performed on 121 of 1,307 patients suspected of having a single type of TIA. This examination supported the diagnosis of TIA in 79 patients and contributed to the establishment of a diagnosis other than TIA in 42. Although the examination increased diagnostic reliability, it did not always result in a definite diagnosis. The most common neurologic findings during a TIA were weakness of an arm or side of the face. Important findings not suggested by history included visual defects and blood pressure fluctuation. Also unexpected were the absence of findings such as sensory deficits in the presence of sensory complaints, retinal emboli, and cardiac abnormalities. Severe arteriosclerotic disease was less evident, the attacks were longer and more severe, and monocular blindness was rare.

Cooperative study of hospital frequency and character of transient ischemic attacks. V. Symptom analysis.

All patients (1,328) suspected of having transient ischemic attacks (TIA) who came to six institutions during a 21-month period were identified. Symptoms and symptom complexes were related to the clinical diagnoses by cross-tabulation, factor analysis, and discriminant analysis. The diagnoses obtained by the discriminant analysis program were comparable to those of reviewing clinical neurologists. Symptoms of importance in the vertebral-basilar system (VBS) were bilateral visual blurring, diplopia, ataxia, and dizziness; In either carotid system (CAS), ipsilateral monocular visual disturbance anc contralateral weakness or sensory complaints; in the left CAS, language disturbances; and in those whose ultimate diagnosis was not TIA, loss of consciousness, confusion, and bilateral leg weakness. Patients with VBS TIAs have symptoms common to conditions that are not TIA and have a greater variety of symptoms and more combinations of symptoms than CAS TIA.