Paraneoplastic Calmodulin Kinase-Like Vesicle-Associated Protein (CAMKV) Autoimmune Encephalitis

OBJECTIVES

To report an autoimmune paraneoplastic encephalitis characterized by immunoglobulin G (IgG) antibody targeting synaptic protein calmodulin kinase-like vesicle-associated (CAMKV).

METHODS

Serum and cerebrospinal fluid (CSF) samples harboring unclassified antibodies on murine brain-based indirect immunofluorescence assay (IFA) were screened by human protein microarray. In 5 patients with identical cerebral IFA staining, CAMKV was identified as top-ranking candidate antigen. Western blots, confocal microscopy, immune-absorption, and mass spectrometry were performed to substantiate CAMKV specificity. Recombinant CAMKV-specific assays (cell-based [fixed and live] and Western blot) provided additional confirmation.

RESULTS

Of 5 CAMKV-IgG positive patients, 3 were women (median symptom-onset age was 59 years; range, 53-74). Encephalitis-onset was subacute (4) or acute (1) and manifested with: altered mental status (all), seizures (4), hyperkinetic movements (4), psychiatric features (3), memory loss (2), and insomnia (2). Paraclinical testing revealed CSF lymphocytic pleocytosis (all 4 tested), electrographic seizures (3 of 4 tested), and striking MRI abnormalities in all (mesial temporal lobe T2 hyperintensities [all patients], caudate head T2 hyperintensities [3], and cortical diffusion weighted hyperintensities [2]). None had post-gadolinium enhancement. Cancers were uterine adenocarcinoma (3 patients: poorly differentiated or neuroendocrine-differentiated in 2, both demonstrated CAMKV immunoreactivity), bladder urothelial carcinoma (1), and non-Hodgkin lymphoma (1). Two patients developed encephalitis following immune checkpoint inhibitor cancer therapy (atezolizumab [1], pembrolizumab [1]). All treated patients (4) demonstrated an initial response to immunotherapy (corticosteroids [4], IVIG [2]), though 3 died from cancer.

INTERPRETATION

CAMKV-IgG is a biomarker of immunotherapy-responsive paraneoplastic encephalitis with temporal and extratemporal features and uterine cancer as a prominent oncologic association. ANN NEUROL 2024.

Assessment of the effects of drugs on memory

This survey is based on 70 controlled investigations of the effects of drugs on memory in healthy volunteers. Although detracting effects were predominant, enhancements were reported as well. The effects of 29 well-known drugs on 15 familiar tests are summarized in a way that permits comparisons of the effects of different drugs and of test sensitivities. There is a discussion of factors that could bias or obscure investigations of the effects of drugs on learning and remembering.

Marijuana effects on the speed of memory retrieval in the letter-matching task

Marijuana's effect on the speed of retrieving simple information from memory was studied using a task in which subjects saw two letters and decided whether or not they had the same name. Subjects smoked a single marijuana or placebo cigarette under double-blind conditions. Marijuana slowed reaction time relative to placebo, but this effect was not influenced by the demands on memory retrieval or by providing advance information relevant to the required decisions, suggesting that memory retrieval was unimpaired.

Marijuana effects on associative processes

Acute marijuana effects on associative processes involved in long-term memory retrieval were studied. Results were partially consistent with expectations based on previous subjective reports that marijuana promotes more uncommon associations. Marijuana altered responses when people gave as many examples of a specified category (e.g., CLOTHING) as they could for 2 min, and when they gave an example of a specified category beginning with a specified letter (e.g., WEAPON - G). Reaction time in the latter task and in prior studies was not altered in the expected manner, a finding problematic for some theoretic interpretations of marijuana's effects on associative processes.

Marijuana effects on semantic memory: verification of common and uncommon category members

Effects of smoked marijuana containing 10 mg delta-9-tetrahydrocannabinol and placebo on retrieval of simple, real-world knowledge in semantic memory were studied. In Exp. 1, subjects (36 men, mean age 23.8 yr.) decided whether an item (e.g. apple) belonged to a specified category (e.g., fruit). In Exp. 2, subjects (40 men, mean age 22.8 yr.) decided whether two items (e.g., apple, peach) belonged to the same category. Marijuana did not alter the normal difference in reaction time between common and uncommon examples of categories, suggesting that effects of marijuana on associations do not derive directly from underlying, general alterations of semantic memory retrieval. Marijuana's effects were not influenced by the demands on memory retrieval or by providing advance information relevant to the required decisions, suggesting memory retrieval was not impaired by this dose of marijuana.

Marijuana effects on visual imagery in a paired-associate task

Marijuana effects on visual imagery, examined using a paired-associate learning task, differed from expectations based on previous subjective reports that marijuana enhances visual imagery. Subjects (48 men, mean age 22.4 yr.) were assigned to four groups (12 subjects per group) differing in (a) whether or not they received specific instructions to use imagery to facilitate learning and (b) whether they received marijuana or placebo. Imagery instructions improved recall, but marijuana did not influence the amount of this improvement. After the memory tests, subjects instructed to use imagery described their images. Marijuana decreased the rated vividness of these imagery descriptions.

Pharmacotherapy for age-related behavioral deficiencies

This review observes a distinction between drugs for treating age-related behavioral losses or impairments among the old and the psychopharmacotherapeutic drugs used in treating disturbed or disordered behavior in adults of various ages. The placebo-controlled studies confirm numerous responses to drugs designed specifically for treating impaired behavior in old people, and the responses of normal or mildly impaired subjects to some of these drugs suggest the possibility of prophylactic applications.

Behavioral toxicity of psychotropic drugs

The present review of psychomotor response to psychotropic substances is restricted to normal subjects and describes responses to the initial standard dose of psychotropic substances in common use. Only placebo-controlled studies which permitted statistical analysis of treatment group differences were considered for the summary. It was revealed that virtually all psychotropic substances have immediate detracting effects. The nature of the effects varied somewhat according to the class of drug. It is suggested that this kind of information has safety implications which could influence the choice of medication.

Somatic discomforts among depressed women

An inventory of 69 somatic discomforts was used to identify those discomforts most likely to be concurrent with a clinically severe depression in a sample of 223 recently hospitalized women. The inventory provided scores for each of 15 classes of discomfort. The classes of discomfort with the highest average score for the depressed sample at admission also yielded significantly lower scores for a nonpatient control sample (P less than .05). The four classes of discomfort most pertinent to depression were designated autonomic, wakefulness, dry mouth, and fatigue. The items of discomfort contributing to these classes showed a statistically significant diminution in severity during treatment (P less than .05).

Psychomotor changes during initial day of benzodiazepine medication

1 The detracting psychomotor effects of diazepam (5 mg three times daily) and clobazam (an investigational 1,5-benzodiazepine) were compared with placebo effects over the course of the initial day of medication. Tests were administered at hourly intervals and the data were analyzed from the standpoint of contrasts at each session and from the standpoint of trends that accrued during the course of the day. 2 It is concluded that among normal volunteers diazepam 5 mg three times daily may be near the threshold for detracting psychomotor consequences during the initial day and that clobazam seems to be without detracting consequences and may have some enhancing effects.

Effects of benzodiazepines on psychomotor performance

1 The literature relating to the effects of benzodiazepines on psychomotor performance is critically reviewed. 2 The multiple and diverse psychomotor tests used are assessed according to their ability to demonstrate differences between drugs. 3 Three general conclusions are: (1) The speed with which simple acts of a repetitive nature are performed may be impaired by benzodiazepines. (2) learning and immediate memory will also be impaired. (3) there is relatively little indication that well established higher mental faculties are adversely involved.

Persisting symptoms in schizophrenia predicted by background factors

A social worker's Home Inquiry was conducted for 75 schizophrenic males as soon as possible after hospitalization. A standard set of items based on this inquiry was scored in terms of nine factors. These Home Inquiry factor scores were found to have modest but statistically significant correlations with specific symptom ratings conducted two years after admission. In the present sample, an interpersonally uncomfortable childhood home and low premorbid self-esteem have untoward implications for the remission of symptoms.

Persisting personalities among depressed women

Descriptions of patients' premorbid personalities were provided by family informants at the time of the depressive episode, and one year later at follow-up the informants were asked to describe the current personalities. A comparison of the initial and follow-up descriptions for a sample of 190 depressive women showed that personality characteristics traditionally ascribed to depressive patients tended to provide a persisting characterization for most of the sample. There was a diminution in the incidence of certain personality characteristics for a small but significant portion of the sample.

Stability of symptom ratings for schizophrenic men

The long form of the Wittenborn Psychiatric Rating Scale was used every six months to rate the symptoms of a sample of 75 schizophrenic men during the 24-month period following their admission to the hospital. The greatest diminution of symptoms assessed in this manner occurred during the first six months of treatment, and rated symptom severity at the time of admission showed relatively little predictive promise for ratings of the respective symptoms at the end of six months. After the initial six-month period, however, the symptoms became increasingly stable and symptom ratings at 12 and 18 months had substantial predictive implications for respective symptom ratings for 24 months. Factor analyses of the intercorrelated scores showed that two transcending patterns were conspicuous throughout the 24-month period.

Contrasts in antidepressant medications

1 Two studies are reviewed, one in depressed patients, the other in healthy volunteers.

2 The effect of nomifensine and imipramine on depressed out-patients has been studied in a controlled double-blind manner. Treatment lasted for 4 weeks and assessments were carried out before and at weekly intervals during the study. These involved use of a self-rating scale and four observer rating scales.

3 In the self-rating scale, 13 of the 14 discriminating items favoured nomifensine, and indicated that it possessed a strengthening or energizing activity, and analysis of individual items on the Hamilton Depression Scale confirmed this.

4 In this study, imipramine showed greater effect on mood and on sleep disturbances.

5 A comparison of nomifensine, imipramine and placebo was carried out in 90 volunteers in a double-blind randomized study. Each volunteer received three doses of medication during the study day.

6 The assessments include a Digit Symbol Substitution Test, the production of a temporal interval, and a simple and a complex test of attention or vigilance.

7 The influence of nomifensine on these tests could not be distinguished from that of placebo. There was evidence, however, that imipramine depressed performance and possessed a sedative effect.

8 The results of both studies, when considered together, are essentially in agreement.

A comparison of the effect of imipramine, nomifensine, and placebo on the psychomotor performance of normal males

Imipramine (50 mg), nomifensine (50 mg) or placebo was administered early morning, late morning, and mid-afternoon to normal volunteers. The program of hourly tests included: the Digit Symbol Substitution, Perceptual Reversal, Time Estimation Test, and Simple and Complex Continuous Performances tests both of which required recognition of briefly exposed letters of the alphabet. It was found that relative to placebo or nomifensine, imipramine had a clearly detracting effect on most of the tests. Drowsiness was reported more often in the imipramine group than in the placebo and nomifensine groups combined.

The effect of minor tranquilizers on psychomotor performance

The effect of a standard daily regimen of chlordiazepoxide, prazepam (a new benzodiazepine tranquilizer), and placebo were examined in a three way double-blind comparison for a sample of normal volunteers. The criteria include a limited spectrum of psychomotor functions. A learning effect was conspicuous for all drugs on all criteria during the day-long sequence of ten trials. For the most part the differences between the drug groups were insignificant, but there were distinctive modifications in the performance of the chlordiazepoxide group. The clearest effect of the tranquilizer medications was found in the time estimation tests. Paradoxically, the drugs correct a naturally occurring perceptual error.

A comparison of antidepressant medications in neurotic and psychotic patients

The responses of 225 newly hospitalized depressed women to amitriptyline hydrochloride, imipramine hydrochloride, and thioridazine were compared with particular reference to the psychotic-neurotic distinction. During the first week, more psychotic patients required sedation and more antidepressant medication than did neurotic patients. All treatment groups showed improvement in psychometric criteria after the first week. There was decreasing improvement through the successive weeks, and no statistically significant differences among treatments emerged. Responses of the neurotic group were superior to those of the psychotic group, but there was no psychometric evidence of interaction between diagnostic classification and treatment effect. The results do not support the hypothesis that any one of these treatments is preferable for neurotic patients or for psychotic patients.

Relation of expressed attitudes to improvement in functional psychotics

The attitudes of a sample of 120 mental hospital patients toward themselves, their future, their symptoms and their hospitalization were correlated with 6 measures of improvement. It was found that the attitudes expressed by the patients were relevant for predicting the outcome of their mental disorder.

Controlled evaluation of nicotinamide adenine dinucleotide in the treatment of chronic schizophrenic patients

On 30 March, 1966, at the Symposium “Enzymes in Mental Health” sponsored by the Carl Neuberg Society for International Scientific Relations, A. Hoffer (1) described the apparently successful treatment in 13 of 17 (acute and chronic) schizophrenic patients in 3 to 5 days by the daily oral use of 1 to 2 grams of nicotinamide adenine dinucleotide (NAD), better known as diphosphopyridinenucleotide (DPN). Widespread publicity given to this announcement attests to the need of more effective treatment for this illness. It also occasioned frequent and persistent inquiry from schizophrenic patients and their relatives as to the suitability of this treatment in their own instance. Rapid confirmation of the findings would justify widespread efforts to evaluate this preparation, whereas failure of confirmation would provide reasonable grounds for a more cautious approach to its use. The members of the Council of the American College of Neuropsycho-pharmacology decided that, as a group of impartial scientists, it would be appropriate for them to carry out such an investigation as rapidly as was compatible with adequate determination of the usefulness of the preparation.