We reviewed previous AASN case reports and systematic case studies, and the results are detailed in Table 2. Since Colan et al. first reported a case of AASN in 1980, together with our patient, there have been 13 patients with detailed information and a diagnosis of AASN. The onset age was 34.15 ± 17.43 years old, with a male to female ratio of 3:10. Among the 13 patients, 11 cases had a prodromic infection, with 7 cases of pulmonary or upper respiratory infection, 1 case of gastrointestinal infection, 2 case of fever, and 1 case of an elevated Epstein-Barr virus (EBV) titer in the blood(2). The interval between the preceding infection and the onset of symptoms was approximately 1–14 days. In all 13 patients, 6 patients initially presented with body pain, 4 with sensory loss, and 3 with gastrointestinal symptoms. Seven of these patients received immunosuppressive treatment (steroids or intravenous immunoglobulin), four of whom were able to walk independently. After treatment, persistent sensoryloss was reported in 8 patients (Table 3).
Table 2
Background of patients with AASN
| Sex | Age/ years | Antecedent events | Duration from antecedent event to initial symptom (days) | Duration from onset to peak (days) | Initial symptoms | High- intensity area in posterior column on MRI | CSF protein (g/l) | Sensory nerve conduction velocity (m/s) median/sural | Nerve biopsy |
Colan, et al.(1) | M | 9 | Pueumonia | ND | 1w | AP, AD, V, D | ND | 0.44 (7 days later: 1.30) | NE/NE | loss of MF, ADG |
Fujii, et al.(2) | F | 23 | EBV(+) | ND | 4 | P | ND | Normal | NE/NE | loss of MF and UMF |
Tohg, et al.(23) | F | 46 | URI | 2w | 1w | N, AD, W | ND | 1.5 | MCV: 40/40 | loss of MF and UMF |
Kanda, et al.(4) | F | 28 | Fever | 2w | 3w | N, U | ND | ND | ND/32 | loss of MF and UMF |
Yasuda, et al.(5) | F | 27 | URI | 10 | 10 | P, D | ་ | ND | NE/NE | ADG |
Yasuda, et al.(5) | F | 44 | URI | 2w | ND | N, W | ་ | ND | NE/NE | ADG |
Yasuda, et al.(5) | F | 65 | No | — | 1w | AP | ND | ND | NE/NE | ND |
Koike, et al.(3) | M | 55 | No | — | 8 | AP, AD | - | 1.16 | NE/NE | loss of MF and UMF |
Koike, et al.(3) | F | 27 | Fever | 6 | 4 | N | - | 1.14 | 60/48 | loss of MF and UMF |
Gales, et al.(24) | M | 26 | GI | 3 | 3w | P | ND | ND | ND/ND | ND |
Enokizono, et al.(25) | F | 6 | URI | 1 | 5 | P | ND | Albumino-cytologic dissociation | NE/NE | ND |
Kim, et al.(6) | F | 38 | URI | 3 | ND | S | ་ | 1.97 | NE/NE | ND |
This Case | F | 50 | PA | 2w | 2w | P | ་ | 1.02 | 48/NE | ND |
AASN: acute autonomic and sensory neuropathy; URI: upper respiratory infection; GI: gastrointestinal infection; PA: pulmonary abscess; ND: not determined; AP: abdominal pain; AD: abdominal distension; V: vomiting; D: diarrhoea; P: pain in the extremities or trunk; N: numbness in the extremities or trunk; W: weakness in the extremities or trunk; U: urinary disturbance; S: syncope; MF: myelinated fibre; UMF: unmyelinated fibre; AXD: axonal degeneration. |
Table 3
Treatment and functional recovery of patients with AASN
| Treatment | Function recovery |
Colan, et al.(1) | Antibiotic | No autonomic symptoms, pain in patchy areas over the body |
Fujii, et al.(2) | — | Improvement of muscle power, severe sensory impairment and diarrhoea |
Tohg, et al.(23) | GC | Improvement of muscle power, persistent autonomic and sensory symptom |
Kanda, et al.(4) | ST | Improvement of OH, persistent urinary retention |
Yasuda, et al.(5) | — | Pain and temperature sensation recovered, abasia |
Yasuda, et al.(5) | — | Pain and temperature sensation recovered, severe ataxic gait |
Yasuda, et al.(5) | — | Pain and temperature sensation recovered, severe ataxic gait |
Koike, et al.(3) | IVIg | Dead |
Koike, et al.(3) | IVIg | Improvement of OH 2 months after onset, able to walk 1 year after onset |
Gales, et al.(24) | IVIg | No symptoms |
Enokizono, et al.(25) | IVIg, GC, antiepileptic therapy | Able to walk 4 months after onset, the vomiting attacks disappeared |
Kim, et al.(6) | IVIg, ST | Improvement of pain and OH |
This Case | GC, IVIg | Improvement of OH, severe pain, severe ataxic gait |
AASN: acute autonomic and sensory neuropathy; GC: glucocorticoid; ST: symptomatic treatment; IVIg: intravenous immunoglobulin; OH: orthostatic hypotension. |
AASN is an acute progressive autonomic and sensory nerve system disease that often secondary to upper respiratory or gastrointestinal infections. The incidence rate of males and females is about 1:2(3). Sensory nerve involvement manifests as hypoesthesia, hyperalgesia, and sensory ataxia in severe cases. Autonomic dysfunction causes gastrointestinal functional disorders, which can lead to abdominal pain, abdominal distension, diarrhea, constipation, and adynamic ileus. Impaired cardiovascular function may cause arrhythmia, orthostatic hypotension, and even syncope. In addition, there may be various manifestations such as abnormal glandular secretion and bladder weakness. The patient in this case presented with general sensory abnormalities and orthostatic hypotension, as well as urinary retention. The Electromyography showed damage to sensory fibers, and MRI imaging showed abnormal signals in the posterior and lateral columns of the spinal cord.
Immune imbalances led by viral infections are likely common causes of AASN(4). There have been reports of EBV infections in previous cases, suggesting that EBV infection may be closely related to the onset of the disease(2). Unlike motor nerves, autonomic and sensory nerves are exposed outside the blood-nerve barrier, making them more vulnerable to attack by antibodies and activated T cells in the blood after viral infection, becoming the primary targets of AASN(5). AASN mainly destroys the dorsal nerve root, resulting in asymmetric, segmental sensory symptoms, accompanied by degeneration of the posterior column of the spinal cord and surrounding nerve trunks. In the early stage of the disease, small neurons are primarily affected, presenting with reduced superficial sensory and autonomic nerve dysfunction. As the disease progresses, larger nerve cells in the ganglions are damaged, leading to sensory ataxia. At this time, MRI may show abnormal signals in the posterior column(3). Kim et al.(6) found that enhanced MRI of AASN patients showed the enhancement in the dorsal nerve roots and posterior column of the spinal cord, suggesting that inflammatory response disrupts the blood-nerve barrier. Consistent with previous studies, the axial T2-weighted cervical-thoracic MRI of our patient showed a high signal intensity in the posterior column of the spianl cord.
Autonomic neuropathy is caused by various reasons, and can be divided into acute or subacute and chronic types based on the onset of the disease(7). Acute or subacute autonomic neuropathy includes autoimmune autonomic ganglionopathy (AAG), paraneoplastic autonomic neuropathy, GBS, and others. AAG is an immune-mediated autonomic neuropathy characterized by orthostatic hypotension, anhidrosis, and severe gastrointestinal motor dysfunction(8). Serum gAChR antibody is a specific diagnostic indicator of AAG, with the antibody titer positively correlated with the severity of the disease(8, 9). Paraneoplastic autonomic neuropathy is secondary to malignant tumors, particularly small cell lung cancer. Antibodies such as anti-Hu, PCA-2, CRMP-5, VGKC, and P/Q type calcium channel antibodies can highly suggest the presence of this disease(10). Sjögren's syndrome is another autoimmune disease characterized by dry eyes and mouth, with autonomic nerve dysfunction symptoms such as arrhythmia, orthostatic hypotension, etc(11). Antibodies against SSA and SSB can highly suggest the presence of this disease(12). GBS is an immune-mediated nerve root neuropathy, mainly characterized by motor and sensory nerve damage. However, it can also affect the autonomic nervous system, resulting in arrhythmia, blood pressure fluctuations, gastrointestinal motor dysfunction, and urinary retention, indicating a poor prognosis(13). In addition, chronic autonomic neuropathy also includes diabetic autonomic neuropathy, amyloidosis, hereditary sensory autonomic neuropathy, and others.
The relationship between AASN and GBS is not clear. Due to prodromic infection and CSF albuminocytologic in AASN patients, some researchers suggest that AASN is a special type of GBS. However, AASN patients only exhibit symptoms of sensory and autonomic nerve involvement, with relatively preserved motor function, so other researchers believe that AASN is an independent autonomic neuropathy. Approximately 6–16% of GBS patients experience symptom relief after treatment, then to worsen again, known as "treatment-related fluctuations" (GBS-TRF)(14). Ruets et al.(15) found 82% of patients with GBS-TRF experienced symptom fluctuations for the first time within 8 weeks of GBS onset, and only 27% showed a second fluctuation, with fewer cases experienced three or more symptom fluctuations. GBS-TRF was more likely to occur in patients with prolonged disease course, longer time to peak symptoms, higher baseline disability scores, and neuropathic pain(16, 17). Our patient also exhibited symptom fluctuations. She received corticosteroid treatment within 3 weeks of onset of symptoms, and experienced partial improvement. After discharge, symptoms worsened. The symptoms gradually worsened during the process of drugs reduction and discontinuation. The patient was subsequently given intravenous immunoglobulin treatment more than two months after the onset of the disease, and the symptoms gradually improved. The symptom fluctuations cannot be ruled out as being related to treatment, there is currently a lack of research on the worsening of symptoms in AASN patients after treatment relief. Our case suggest that the early treatment may block the immune process, but early interruption of treatment will lead to recurrent disease course. Further research is needed to explore the mechanisms and risk factors for symptom fluctuations in AASN patients.
Currently, there are no specific treatments for AASN. Clinically, immunomodulatory therapy and symptomatic treatment can be performed. Corticosteroids or intravenous immunoglobulin may slow the progression of the disease and improve the patients' symptoms to some extent(18). Symptomatic treatment for AASN patients can alleviate their pain, improve outcomes, and help maintain their quality of life. Parasympathetic stimulants such as carbachol and methacholine can alleviate pupillary, intestinal and bladder dysfunction. Mineralocorticoids, droxidopa, and midodrine can be used to treat orthostatic hypotension(19, 20). For patients with supine hypertension, short-acting antihypertensive drugs such as angiotensin II receptor blockers (losartan) and calcium channel blockers (nifedipine) can help control blood pressure(21). Patients with tachycardia may be treated with β-receptor antagonists after exclusion of cardiac disease. With treatment, AASN patients experience some improvement in autonomic nerve symptoms, but sensory symptoms tend to recover less favorably, and the presence of sensory ataxia indicates a poor prognosis(3). Furthermore, substantial neuronal damage is indicated by high neuron-specific enolase (NSE) levels in the CSF, which is associated with a poor prognosis(22).
Early identification and prompt treatment of AASN are important for improving disease outcomes, survival rates, and quality of life. AASN should be highly suspected in patients who present with symptoms of autonomic dysfunction and the presence of abnormal pain or limb numbness with relatively preserved motor function. In order to determine whether the disease has a history of prior infections and its onset features, a complete medical history should be obtained. Additionally, an objective neurological examination and autonomic nervous function assessment should be carried out. Spinal MRI, lumbar puncture, NCS, and sural nerve biopsy can help increase the diagnosis rate and distinguish AASN from other autonomic neuropathies. It should be emphasized that timely and effective treatment before deep sensory involvement can effectively delay the progression of the disease and improve prognosis. Corticosteroids or intravenous immunoglobulin may be effective treatments for AASN. During the treatment process, giving varying doses of treatment according to the severity of the patient's condition can bring better treatment outcomes to patients and avoid irreversible damage to the sensory and autonomic nerves caused by symptom fluctuations of the disease.