Age: 69.0
Sex: M
Vaccine: COVID19, COVID19
Symptoms: Herpes simplex test negative, Hypermetabolism, Immunoglobulin therapy, Laboratory test normal, Lumbar puncture abnormal
Clinical narrative: Patient admitted to the facility twice for AMS, March 6th-14th 2022 and April 2nd-22nd 2022. The first of these hospitalization is summarized as follows: His recent history is notable for an admission to the neurology service in March 2022 for altered mental status, weakness and left arm shaking. His hospital course was notable for a detected R posterior cerebral lesion, c/f encephalitis vs late subacute infarct. An LP was performed, which ruled out infectious causes but was possibly concerning for an autoimmune etiology (with mildly elevated protein, miledly elevatead WBC, and elevated Serum QIG IgA), indicated for continued workup. He was started on IVIG on 3/14 out of concern for autoimmune encephalitis but only completed a two day course. Rheumatology was e-consulted and felt that his +ANA IFA screen 1/160 was unlikely to be due to an autoimmune process given abscence of other autoimmune findings. His hospital course at that time was also complicated by focal epilepsy, which was felt to be provoked in the setting of aspiration pneumonia.  Second hospitalization is summarized as follows: Differential includes sequelae of status epilepticus, autoimmune/paraneoplastic encephalitis,cns primary maligancy and MELAS. MELAS would be rare in this age group, however there are case reports of onset in the 6th and 7th decade of life. While MELAS is unlikely to be unimodal, the patient does have an older R temporoparietal infarct present on MRI in 6/21. Hypermetabolism on PET was initially thought to be less consistent with MELAS, given that hypometabolism on PET is a more typical finding. However, this hypermetabolism on PET may be better explained by ongoing seizure activity, which is a less common, but known, complication of MELAS. More also, he also came with gram negative bacteremia and UTI (Probably due to BPH VS prostate cancer)  which could have contributed to his altered mental status. AMS wise, he continues to have difficulties with following commands, comprehending and some repitition.Note here that the patient word finding difficulties were present since 2021. Mainly, he has non fluent aphasia, not able to name, read, or comprehend.  His writing is intact. MRI repeat shows improvement. We discussed the case with Dr. at facility and Dr, who have all come to agree that the pattern of findings on MRI are more concerning of MELAS than infection/inflammatory.  Neurology team wanted to repeat LP to send ENC2, lactate and pyruvate, however, the patient was not able to tolerate the first LP. Since the clinical picture seems to head towards MELAS, we decided to go ahead and order genetic testing and send ENS2. Please note that Lab was not authorizing to send to Lab, wanted ENS2 send to quest. Lab has more test on the  panel than quest. Another ddx still included Hashimoto and encephalitis. Anti tpo, repeat TFTs, Anti thyroglobin were all negative. Repeat PET scan now shows hypometabolism in the right parietal, occipital and posterior temporal love. There is an intense focal hypermetabolism in left mesial posterior temporal lobe.