Defining the Clinicoradiologic Syndrome of SARS-CoV-2 Acute Necrotizing Encephalopathy: A Systematic Review and 3 New Pediatric Cases

BACKGROUND AND OBJECTIVES: We characterize clinical and neuroimaging features of SARS-CoV-2-related acute necrotizing encephalopathy (ANE). METHODS: Systematic review of English language publications in PubMed and reference lists between January 1, 2020, and June 30, 2023, in accordance with PRISMA guidelines. Patients with SARS-CoV-2 infection who fulfilled diagnostic criteria for sporadic and genetic ANE were included. RESULTS: From 899 articles, 20 cases (17 single case reports and 3 additional cases) were curated for review (50% female; 8 were children). Associated COVID-19 illnesses were febrile upper respiratory tract infections in children while adults had pneumonia (45.6%) and myocarditis (8.2%). Children had early neurologic deterioration (median day 2 in children vs day 4 in adults), seizures (5 (62.5%) children vs 3 of 9 (33.3%) adults), and motor abnormalities (6 of 7 (85.7%) children vs 3 of 7 (42.9%) adults). Eight of 12 (66.7%) adults and 4 (50.0%) children had high-risk ANE scores. Five (62.5%) children and 12 (66.7%) adults had brain lesions bilaterally and symmetrically in the putamina, external capsules, insula cortex, or medial temporal lobes, in addition to typical thalamic lesions of ANE. Hypotension was only seen in adults (30%). Hematologic derangements were common: lymphopenia (66.7%), coagulopathy (60.0%), or elevated D-dimers (100%), C-reactive protein (91.7%), and ferritin (62.5%). A pathogenic heterozygous c/.1754 C>T variant in RANBP2 was present in 2 children: one known to have this before SARS-CoV-2 infection, and a patient tested because the SARS-CoV-2 infection was the second encephalopathic illness. Three other children with no prior encephalopathy or family history of encephalopathy were negative for this variant. Fifteen (75%) received immunotherapy (with IV methylprednisolone, immunoglobulins, tocilizumab, or plasma exchange): 6 (40.0%) with monotherapy and 9 (60.0%) had combination therapy. Deaths were in 8 of 17 with data (47.1%): a 2-month-old male infant and 7 adults (87.5%) of median age 56 years (33-70 years), 4 of whom did not receive immunotherapy. DISCUSSION: Children and adults with SARS-CoV-2 ANE have similar clinical features and neuroimaging characteristics. Mortality is high, predominantly in patients not receiving immunotherapy and at the extremes of age.

Clonic seizures, continuous spikes-and-waves during slow sleep, choreoathetosis and response to sulthiame in a child with FRRS1L encephalopathy.

BACKGROUND: Ferric chelate reductase 1 like (FRRS1L) encephalopathy is a rare cause of developmental and epileptic encephalopathy. Only a few cases have been reported thus far and seizures tend to be drug refractory. We report an additional case to highlight the good seizure response to sulthiame. CASE REPORT: A boy from non-consanguineous parents presented with history of 'abnormal movements' from 7 months of age. At one year of age, video electroencephalogram (EEG) monitoring demonstrated the 'abnormal movements' to be clonic seizures. Valproate, lamotrigine and clobazam combination were only partially effective at reducing the seizures. Repeat EEG at 1 year 8 months old revealed a continuous spikes-and-waves during slow sleep (CSWS) pattern, prompting a trial of sulthiame. After 2 weeks of sulthiame, seizures ceased completely. The clonic seizures recurred at age 4 years when sulthiame supply was interrupted, but the seizures promptly remitted following sulthiame's resumption. Subtle choreiform movements appeared from age one year and later became more prominent. Whole exome sequencing (WES) identified a homozygous novel variant (nonsense) in the FRRS1L gene (NM_014334.3: c.670C>T:p.Gln224*). He has been seizure free since 4 years of age but remained profoundly delayed. CONCLUSION: Sulthiame may have a role in the early treatment of seizures in children with refractory epilepsy due to FRRS1L mutation.

Atypical childhood chronic inflammatory demyelinating polyneuropathy.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an uncommon cause of progressive weakness in childhood. The diagnosis is easy when the clinical history and findings are supported by unequivocal electrophysiologic and laboratory evidence of demyelination, but it can be challenging if the criteria for demyelination are not met. We report a case of atypical childhood CIDP to highlight the diagnostic difficulties and the importance of recognizing this treatable condition.

Intrinsic epileptogenicity of cortical tubers revealed by intracranial EEG monitoring.

OBJECTIVE: We sought to identify intracranial EEG patterns characteristic of epileptogenic tubers and to understand the contribution of perituberal cortex. METHODS: Twenty-three intracranial EEG monitoring studies were reviewed from 17 children aged 1.3-7.7 years with tuberous sclerosis complex and intractable multifocal epilepsy, 14 with a history of epileptic spasms. Interictal epileptiform discharges and ictal rhythms for 60 electroclinically distinct seizures (EDS) were analyzed in relation to 162 sampled tubers. RESULTS: Localized, tuber-related, ictal rhythms were seen in 49/60 EDS, most commonly as low-voltage fast activity recruiting to rhythmic spiking, then diffuse slowing or bursts of ripple range activity. Ictal onset in localized EDS involved only tubers in 57% and tubers with perituberal cortex in 31%. Ictal fast ripples (FR) noted at seizure onset in 15/38 localized EDS were confined to tubers in 73% and involved tuber with perituberal cortex in 27%. Intraictal activation occurred during seizure propagation in 19 localized EDS, being to tubers in 63% and to tubers with perituberal cortex in 37%; 63% of activated tubers generated independent EDS. Trains of periodic sharp waves on an attenuated background were seen interictally at 36/162 tubers, with 67% of those tubers generating EDS (p = 0.0001). Interictal FR, when present, involved tubers more commonly than perituberal cortex but were not associated with EDS. CONCLUSION: The study demonstrates interictal and ictal intracranial EEG findings characteristic of epileptogenic tubers, suggests that tubers play a greater role in seizure genesis than perituberal cortex, and suggests tuberectomy may be a sufficient surgical approach in a number of patients.

Temporoparietooccipital disconnection in children with intractable epilepsy.

OBJECT: Temporoparietooccipital (TPO) disconnection is described mainly in children with diffuse posterior quadrant lesions and concordant electroencephalography (EEG) findings. The authors report on 16 children who underwent TPO surgery, including 4 with no definite epileptogenic lesion and 8 with generalized electroclinical manifestations. METHODS: The authors conducted a retrospective review of clinical, neuropsychological, EEG, imaging, and histopathological data in 16 children with intractable epilepsy who underwent TPO disconnection and/or resection at their center between December 1998 and March 2010. RESULTS: Seizure onset occurred between the ages of 1 and 24 months, and TPO surgery was performed between the ages of 0.2 and 17 years. All children had refractory seizures, including epileptic spasms in 10 and tonic seizures in 7, and all had developmental delay. Twelve children had epileptogenic lesions on MR imaging, including 6 with posterior quadrant dysplasia. Four children had only subtle white matter signal change or unusual sulcation on MR imaging, associated with subtle but concordant EEG and functional imaging abnormalities. After a mean follow-up of 52 months (range 12-114 months), 9 children (56%) are seizure-free and 5 (31%) experienced seizure reduction of greater than 50%. Focal or regional background slowing on EEG was correlated with favorable seizure outcome. Five children showed developmental progress and 3 had acceleration in development following surgery. None of the children developed new motor deficits postoperatively. CONCLUSIONS: Temporoparietooccipital disconnection is an effective, motor-sparing epilepsy surgery procedure for selected children with refractory focal or generalized seizures with localization to the posterior quadrant on 1 side, with or without a discrete lesion on MR imaging.