Familial Occurrence and Heritable Connective Tissue Disorders in Spontaneous Intracranial Hypotension

Genetic factors often are implicated in the etiology and pathogenesis of spontaneous spinal CSF leaks. Nevertheless, the familial occurrence of spontaneous intracranial hypotension (SIH) and the prevalence of heritable connective tissue disorders (hCTDs) have never been studied in large patient series. The purpose of this study was to determine the frequency of familial SIH and of hCTDs in a large cohort of patients with SIH.

In this single-center retrospective observational study, data elements indicating familial SIH and presence of hCTDs were extracted from a prospectively maintained database. In this database, the patients' clinical characteristics, including family history of SIH and diagnosis of hCTD, are abstracted prospectively and updated with each change or addition to the data elements. We studied the time period between January 1, 2001 and December 31, 2023.

Among 1945 patients with SIH, 12 patients (0.62%) from 9 different families (0.46%) had a family history of SIH (12 patients were evaluated in person and 6 patients were not evaluated in person). There were 2 affected family members in each family. The 18 affected family members included 2 men and 16 women (mean age: 44.2 years [range, 21-65 years]). Three patients of 2 different families with a family history of SIH had been diagnosed with a monogenetic hCTD. Overall, 41 (2.1%) of the 1945 patients had a monogenetic hCTD. Thus, 3 patients (7.3%) from 2 families (4.9%) of 41 patients with SIH with a monogenetic hCTD had a family history of SIH compared with 10 patients (0.53%) from 7 families (0.37%) among 1904 patients with SIH who did not have a monogenetic hCTD (P = .0015).

The occurrence of SIH among first-degree family members suggests the importance of genetic factors but is rare and hCTDs are uncommon among the entire SIH population. These findings support the notion that SIH is a multifactorial disorder. Further research is crucial to elucidate genetic and acquired factors in the development of spontaneous spinal CSF leaks. For now, patients can be reassured that the risk of, for example, their offspring developing a spontaneous CSF leak-a commonly voiced concern-is not particularly high.