IntroductionHaNDL is a rare neurological disorder of unknown aetiology that is characterised by headache, neurological deficit and pleocytosis in the cerebrospinal fluid (CSF). It is a benign condition that has spontaneous resolution of symptoms within months.A 50 year old female presented to Emergency with an acute focal neurological deficit of right sided weakness, dysphasia and dysarthria lasting less than one hour. Over the preceding months she had a new onset of headache. She was worked up for a likely diagnosis of TIA.MethodsCase report.ResultsInitial CT Brain(angiography) showed no stroke or other identifiable cause of symptoms.MRI brain showed excessive nonspecific T2 hyperintensities, requiring further investigation for possible vasculitis. MR angiography was normal and there was no evidence of stroke.Viral PCR’s were negative.Lumbar puncture (LP) showed pleocytosis (leucocytes 309×10E6/L), raised intracranial pressure and high protein, raising suspicion for HaNDL. This normalised on subsequent outpatient LP, along with symptoms.ConclusionsA diagnosis of HaNDL is made as a diagnosis of exclusion, though should be considered as a differential diagnosis for various presentations in which transient acute focal neurology is a presenting complaint.Due to relatively few reported cases of HaNDL, it is possible that HaNDL is being underdiagnosed due to variability in patient presentation and lack of understanding of the syndrome.As in this case, when a patient presents with transient acute focal neurology in the absence of headache as a prominent presenting symptom, it is reasonable to consider HaNDL as a differential diagnosis.