Acute confusional state in HaNDL syndrome

To assess epidemiological, clinical and neuroimaging features of acute confusional state in the Headache and Neurological Deficits with cerebrospinal fluid Lymphocytosis (HaNDL) syndrome.

HaNDL is an increasingly recognized syndrome in which migraine-like headache episodes accompanied by hemiparaesthesia and/or hemiparesis and/or dysphasia are associated to CSF lymphocytic pleocytosis. The International Classification of Headache Disorders (ICHD-3) includes HaNDL syndrome in group 7 "headache attributed to non-vascular intracranial disorder" code 7.3.5, and lists the HaNDL-associated signs/symptoms that may be found less frequently. Confusional state is not mentioned in the 7.3.5-ICHD-3 "notes" or "comments" section as part of the HaNDL neurological spectrum. Moreover, the acute confusional state pathogenesis in HaNDL syndrome remains still uncertain and debated.

Here, we report a 32-year-old male who complained episodes of migraine-like headache and left hemiparaesthesia complicated by confusional state which led to discovering CSF lymphocytosis. Since other workup to determine the cause of his symptoms was otherwise negative, he was diagnosed as having HaNDL syndrome. We also ascertained and reviewed all available reports of HaNDL to assess the significance of confusional state in this syndrome.

The search yielded 159 HaNDL cases among single reports and small/large series. Out of 159 patients who fulfilled the inclusion criteria for HaNDL according to the current ICHD at the time of diagnosis, 41 (25.7%) presented with acute confusional state. Among 41 HaNDL patients with confusional state, 16 (66.6%) out of 24 who underwent spinal tap had increased opening pressure.

We propose that a mention of acute confusional state may be included in the "comments" section of "7.3.5-syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL)," when ICHD-3 diagnostic criteria will be updated. Moreover, we speculate that intracranial hypertension may play a role in the pathogenesis of the acute confusional state associated to HaNDL syndrome. Larger case series are needed to evaluate this hypothesis.