Introduction The syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL) is a diagnosis made by exclusion. In the literature, different etiological explanations are proposed for HaNDL, including an immune-mediated reaction after a viral infection. Case description We present a case of a 23-year-old woman with several episodes of transient headache, neurological deficits and cerebrospinal fluid lymphocytosis. All diagnostic criteria for the HaNDL syndrome were fulfilled; however, additional cerebrospinal fluid analysis showed a positive polymerase chain reaction (PCR) for human herpes virus type 7 (HHV-7). Discussion The possible role of a (prodromal) viral infection in the etiology of HaNDL is discussed. Also the role of electroencephalography (EEG) recordings is discussed. Serial EEG recordings showed generalized slowing, frontal intermittent rhythmic delta activity (FIRDA) and symmetric triphasic frontal waves with a dilation lag.
Keywords: Syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL); electroencephalography (EEG); frontal intermittent rhythmic delta activity (FIRDA); human herpes virus type 7 (HHV-7); triphasic waves.