LGI1 encephalitis: a disease of jerks and confusion

Abstract

Limbic encephalitis is a group of immune-mediated disorders that includes the classic paraneoplastic encephalitic syndrome and the recently described non-paraneoplastic autoimmune encephalitis most of which target the extracellular antigens. We present a case of 70-year-old man who presented with rapidly progressive cognitive decline and refractory faciobrachial dystonic seizures and demonstrated seropositivity for leucine-rich, glioma-inactivated protein 1 antibodies. After immunomodulation, the patient had dramatic improvement in the cognitive functioning and in seizure control.

Recognition of seizure semiology and semiquantitative FDG‐PET analysis of anti‐LGI1 encephalitis

“…Considerable research efforts have illustrated the limited and rigid metabolic pattern of anti‐LGI1 AE. 3 , 7 , 16 , 18 , 19 , 26 , 29 , 30 , 31 During the FBDS stage, patients usually have hypermetabolism in the contralateral basal ganglia, 3 , 16 , 26 , 30 , 31 sometimes accompanied by abnormal metabolism of the cortex, 5 , 32 , 33 indicating complex cortical–subcortical interactions. 26 Altered basal ganglia and MTL metabolism were found in 63%–70% and 70%–75% of cases, respectively, during the limbic encephalitis stage.…”

Cognition and psychopathology in autoimmune encephalitides: A focus on risk factors and patient outcomes

“…Clinicians should be alert to generalized neuropsychiatric symptomology, as this is commonly reported in acute stages of AE. Reported symptomology has included apathy and lethargy, increased irritability, aggressiveness and agitation, adynamic behavior, and indifference, as well as new‐onset anxiety and depressive symptomology 11,12,18–28 . Consequently, detailed assessment of psychopathology should be carried out as standard practice when AE is suspected.…”

“…In the AE, the dysfunction is postulated to be associated with disruption to neuronal circuity secondary to disruption to receptor systems, as observed in models of anti‐NDMAR AE (discussed later). It is important to note, however, that acute memory impairments have also been noted in patients with unremarkable or non‐specific clinical imaging 3,15,18,21,34 …”

“…Reported symptomology has included apathy and lethargy, increased irritability, aggressiveness and agitation, adynamic behavior, and indifference, as well as new-onset anxiety and depressive symptomology. 11,12,[18][19][20][21][22][23][24][25][26][27][28] Consequently, detailed assessment of psychopathology should be carried out as standard practice when AE is suspected. Such assessment should encompass questioning of the individual, but noting an informative history is essential to determine the onset and natural history of symptom progression.…”

“…It is important to note, however, that acute memory impairments have also been noted in patients with unremarkable or non-specific clinical imaging. 3,15,18,21,34 In addition to memory dysfunction, psychometric investigations have shown impairments across a number of domains in the acute stage of the AE, as indicated by poor performance on cognitive tests.…”