Familial Hemiplegic Migraines and Baseline Neuropsychological Testing: A Case Report

Hemiplegic Migraine

PURPOSE OF REVIEW

In this article, we review recent updates to the epidemiology, diagnostic testing, genetics, pathophysiology, and management of hemiplegic migraine.

RECENT FINDINGS

While three genes have been historically associated with hemiplegic migraine, recent studies suggest two additional genes may also be implicated including PPRT2 and SLC1A3. Hemiplegic migraine is a severe subset of migraine with aura with symptoms including reversible hemiparesis in addition to other aura symptoms such as visual, sensory, or speech. The exact pathophysiology of hemiplegic migraine is not clear, but it is thought that this phenomenon is due to neuronal and glial depolarization causing cortical spreading depression. Due to the severity of presentation as well as the numerous mimickers, it is important to know a comprehensive differential and work-up. Given the low prevalence of the disease, most studies regarding treatment are limited to case studies. There is still an important need for further and larger studies regarding management of these cases.

Two distinct phenotypes, hemiplegic migraine and episodic Ataxia type 2, caused by a novel common CACNA1A variant

BACKGROUND

To investigate the genetic and environmental factors responsible for phenotype variability in a family carrying a novel CACNA1A missense mutation. Mutations in the CACNA1A gene were identified as responsible for at least three autosomal dominant disorders: FHM1 (Familial Hemiplegic Migraine), EA2 (Episodic Ataxia type 2), and SCA6 (Spinocerebellar Ataxia type 6). Overlapping clinical features within individuals of some families sharing the same CACNA1A mutation are not infrequent. Conversely, reports with distinct phenotypes within the same family associated with a common CACNA1A mutation are very rare.

CASE PRESENTATION

A clinical, molecular, neuroradiological, neuropsychological, and neurophysiological study was carried out in proband and his carrier mother. The new heterozygous missense variant c.4262G > A (p.Arg1421Gln) in the CACNA1A gene was detected in the two affected family members. The proband showed a complex clinical presentation characterized by developmental delay, poor motor coordination, hemiplegic migraine attacks, behavioral dysregulation, and EEG abnormalities. The mother showed typical episodic ataxia attacks during infancy with no other comorbidities and mild cerebellar signs at present neurological evaluation.

CONCLUSIONS

The proband and his mother exhibit two distinct clinical phenotypes. It can be hypothesized that other unknown modifying genes and/or environmental factors may cooperate to generate the wide intrafamilial variability.

Familial Hemiplegic Migraine With Progressive Cerebellar Ataxia Caused by a p.Thr666Met CACNA1A Gene Mutation in a Chinese Family

Here, we describe the first case of familial hemiplegic migraine type 1 (FHM1) resulting from a T666M mutation in the CACNA1A gene of a Chinese individual. A 54-year-old female patient demonstrated extensive clinical manifestations, including transient paropsia, hemianesthesia, logaphasia, hemiplegia, migraine, fever, impaired consciousness, and progressive cerebellar ataxia. At admission, neurological examination showed a fever of 38.6°C, coma, bilateral pupillary constriction, left-sided deviation of both eyes, meningeal irritation, and bilateral positive Chaddock's sign. Brain magnetic resonance imaging (MRI) displayed only cerebellar atrophy. The pressure and white blood cells of the cerebrospinal fluid (CSF) were elevated. Her nine relatives also had similar clinical spectra. To further clarify the diagnosis, we conducted a genetic analysis on the family. The results of genetic testing showed that all seven living affected members carried the T666M mutation in the CACNA1A gene. This case report indicates that the diagnosis of FHM should be taken into account when a patient manifests migraine accompanied with hemiplegia, acute encephalopathy, and abnormal CSF. In addition, genetic testing is indispensable for the identification of some atypical attacks of hemiplegic migraine.