Dysautonomia in anti-Hu paraneoplastic neurological syndromes.

BACKGROUND AND OBJECTIVES: Dysautonomia has been associated with paraneoplastic neurological syndrome (PNS)-related mortality in anti-Hu PNS, but its frequency and spectrum remain ill-defined. We describe anti-Hu patients with dysautonomia, estimate its frequency, and compare them to patients without dysautonomia. METHODS: Patients with anti-Hu antibodies diagnosed in the study centre (1990-2022) were retrospectively reviewed; those with autonomic signs and symptoms were identified. RESULTS: Among 477 anti-Hu patients, 126 (26%) had dysautonomia (the only PNS manifestation in 7/126, 6%); gastrointestinal (82/126, 65%), cardiovascular (64/126, 51%), urogenital (24/126, 19%), pupillomotor/secretomotor (each, 11/126, 9%), and central hypoventilation (10/126, 8%). Patients with isolated CNS involvement less frequently had gastrointestinal dysautonomia than those with peripheral (alone or combined with CNS) involvement (7/23, 30% vs. 31/44, 70% vs. 37/52, 71%; P = 0.002); while more frequently central hypoventilation (7/23, 30% vs. 1/44, 2.3% vs. 2/52, 4%; P < 0.001) and/or cardiovascular alterations (18/23, 78% vs. 20/44, 45% vs. 26/52, 50%; P = 0.055). Median [95% CI] overall survival was not significantly different between patients with (37 [17; 91] months) or without dysautonomia (28 [22; 39] months; P = 0.78). Cardiovascular dysautonomia (HR: 1.57, 95% CI [1.05; 2.36]; P = 0.030) and central hypoventilation (HR: 3.51, 95% CI [1.54; 8.01]; P = 0.003) were associated with a higher risk of death, and secretomotor dysautonomia a lower risk (HR: 0.28, 95% CI [0.09; 0.89]; P = 0.032). Patients with cardiovascular dysautonomia dying ≤ 1 year from clinical onset had severe CNS (21/27, 78%), frequently brainstem (13/27, 48%), involvement. DISCUSSION: Anti-Hu PNS dysautonomia is rarely isolated, frequently gastrointestinal, cardiovascular and urogenital. CNS dysfunction, particularly brainstem, associates with lethal cardiovascular alterations and central hypoventilation, while peripheral involvement preferentially associates with gastrointestinal or secretomotor dysautonomia, being the latest more indolent.

Peripheral nervous system involvement accompanies central nervous system involvement in anti-glial fibrillary acidic protein (GFAP) antibody-related disease.

BACKGROUND: Glial fibrillary acidic protein (GFAP) is expressed by astrocytes in the central nervous system (CNS), but also by immature and regenerative Schwann cells in the peripheral nervous system (PNS). GFAP antibodies (GFAP-Abs) in cerebrospinal fluid (CSF) have been mainly described in patients with meningoencephalomyelitis. We aimed to study PNS symptoms in patients with CSF GFAP-Abs. METHODS: We retrospectively included all patients tested positive for GFAP-Abs in the CSF by immunohistochemistry and confirmed by cell-based assay expressing human GFAPα since 2017, from two French reference centers. RESULTS: In a cohort of 103 CSF GFAP-Abs patients, 25 (24%) presented with PNS involvement. Among them, the median age at onset was 48 years and 14/25 (56%) were female. Abnormal electroneuromyography was observed in 11/25 patients (44%), including eight isolated radiculopathies, one radiculopathy associated with polyneuropathy, one radiculopathy associated with sensory neuronopathy, and one demyelinating polyradiculoneuropathy. Cranial nerve involvement was observed in 18/25 patients (72%). All patients except one had an associated CNS involvement. The first manifestation of the disease concerned the PNS in three patients. First-line immunotherapy was administered to 18/24 patients (75%). The last follow-up modified Rankin Scale was ≤ 2 in 19/23 patients (83%). Patients with PNS involvement had significantly more bladder dysfunction than patients with isolated CNS involvement (68 vs 40.3%, p = 0.031). CONCLUSIONS: PNS involvement in GFAP-Abs autoimmunity is heterogeneous but not rare and is mostly represented by acute or subacute cranial nerve injury and/or lower limb radiculopathy. Rarely, PNS involvement can be the first manifestation revealing the disease.