A 31-year old male with a background of occasional Migraine without aura and mechanical lower back pain, presented with recurrent transient episodes of generalised headache, speech impairment, confusional state, and hemi-body sensory-motor symptoms. He had 9-10 episodes over a 2-week period. These were sudden, non-stereotypical, and lasted between 30-120 minutes. He was well in between and the very first episode happened just before his travel to the Canaries for holidays. He had 3 separate admissions with these episodes.

Routine blood tests were normal Contrast CT head and MRI brain showed transient generalised leptome- ningeal enhancement, CSF showed sequential WCC of 420 and 200 before returning to normal. Repeat EEG showed no epileptiform abnormality. Extensive tests for infectious agents including viral serology were all either negative or suggestive of previous exposure. Only HSV-7 PCR was positive. Inflammatory and paraneoplastic tests were negative. He fully recovered from these in 2 months with no sequelae.

The clinical Syndrome of transient Headache and Neurological Deficits with cerebrospinal fluid Lympho- cytosis (HaNDL) is well described, rarely seen and poorly understood. Proposed mechanisms include migraine pathophysiology, post-infectious and immunological phenomenon. This is the first report of an active HSV-7 infection, causing HaNDL.