Paraneoplastic Limbic Encephalitis (PLE) is a neurologic disorder associated with an underlying malignancy. It may occur alone or mixed with other neurologic paraneoplastic disorders (paraneoplastic encephalomyelitis).


Clinical features:

(1) personality changes including disinhibition

(2) irritability

(3) psychiatric changes (depression, hallucinations, affective changes)

(4) seizures

(5) short term memory loss

(6) space and time disorientation with or without dementia


Criteria for diagnosis - one of the following (Gultekin, 2000):

(1) neuropathologic examination

(2) all 4 of the following:

(2a) compatible clinical features

(2b) interval < 4 years between development of neurologic disorder and diagnosis of the underlying tumor (PLE may precede tumor diagnosis)

(2c) exclusion of other neuro-oncological complications (brain metastases, toxic encephalopathy, metabolic encephalopathy, viral encephalitis, nutritional deficit, cerebrovascular disorder)

(2d) one or more of the following:

(2d1) CSF showing chronic inflammatory changes but negative for malignant cells

(2d2) temporal lobe abnormalities on MRI (increased signal on T2-weighted images or atrophy on T1-weighted sequences of the medial aspect)

(2d3) epileptic activity in the temporal lobes on EEG


The identification of one of the autoantibodies supports the diagnosis of paraneoplastic syndrome. These may be detected in serum and CSF.


Associated Tumor


small cell lung carcinoma

anti-Ta (anti-Ma2)

testicular germ cell tumor

other or none

lung, breast, Hodgkin's disease, esophagus, colon, urinary bladder, thymoma


Patients may show clinical improvement with treatment of the underlying malignancy.


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