Table 1.

Clinical features, CSF and neuroimaging findings

Case	Sex/age	Limbic encephalitis (LE): presenting symptoms	CSF	Initial brain MRI	Brain FDG-PET
1	M/60	Hippocampal syndrome: short-term memory loss, confusion, partial complex seizures, diaphoresis, and palinopsia Other: akathisia, fasciculations, hyponatraemia	0 WBC, protein 63, glucose 64, OB not examined, no ISAb IgG index not examined	FLAIR, T2 abnormalities in medial temporal lobes. No contrast enhancement	Hypermetabolism in medial temporal lobes
2	F/65	Hippocampal syndrome: short-term memory loss, confusion and irritability Other: downbeat nystagmus, abnormal behaviour, increased fluid intake	30 WBC, protein 97, glucose 59, positive OB, positive ISAb IgG index 1.24	Mild FLAIR abnormalities in medial temporal lobes. No contrast enhancement	Diffuse decreased metabolism
3	F/44	Extensive LE: psychiatry admission for acute agitation, personality change, memory loss, generalized tonic–clonic seizures Other: word finding difficulty, mild right hemiparesis	15 WBC, protein 18, glucose 90, no OB, ISAb not examined IgG index <0.66	Non-specific, scattered T2 foci of hyperintensity in frontal lobes. No contrast enhancement	Hypermetabolism in left frontal–temporal region
4	F/26	Extensive LE: psychiatry admission for acute change in behaviour, confusion, generalized tonic–clonic seizures Other: central hypoventilation, ankle clonus and left Babinski sign	49 WBC, protein 67, glucose 66, OB not examined, positive ISAb IgG index not examined	FLAIR and T2 abnormalities in cerebral cortex and cerebellum with cerebellar contrast enhancement	Increased metabolism in right temporal lobe and brainstem; decreased metabolism in occipital lobes
5	F/44	Hippocampal syndrome: pure short-term memory loss Evolved to extensive LE, focal motor seizures	44 WBC, protein 91, glucose 70, no OB, positive ISAb IgG index <0.66	Initial MRI normal. Follow-up 5 days later: mild temporal lobe FLAIR abnormalities (right > left). No contrast enhancement	Increased metabolism in right temporal lobe and left cerebellum
6	M/38	Extensive LE: confusion, agitation, short-term memory loss, generalized tonic–clonic seizures (prior episode of LE 5 years earlier) Evolved to hippocampal and multifocal encephalitis, and stiff-person syndrome	7 WBC, protein 50, glucose 92, positive OB, positive ISAb IgG index not examined	FLAIR abnormalities in right medial and lateral temporal lobe, right frontal, left insular and left occipital regions. No contrast enhancement	Not done
7	M/55	Hippocampal syndrome: short-term memory loss Evolved to cerebellar and brainstem dysfunction; partial complex seizures	81 WBC, protein 150, glucose 59, positive OB, positive ISAb IgG index 40.1	Persistent FLAIR, T2 abnormalities in medial temporal lobes. Positive contrast enhancement. Evolving hippocampal atrophy	Increased metabolism in temporal lobes, right insula and cerebellum

OB = oligoclonal bands; ISAb = intrathecal synthesis of antibodies; IgG index (<0.66). CSF normal values: glucose 55–80 mg/dl; protein 16–46 mg/dl; white blood cells (WBC) <4/μl.