Syndrome of inappropriate secretion of antidiuretic hormone associated with multiple sclerosis

Pearls & Oy-sters: Syndrome of Inappropriate Antidiuretic Hormone Secretion Presenting as Neuromyelitis Optica Spectrum Disorder Flare

While it was previously believed that neuromyelitis optic spectrum disorder (NMOSD) mostly affected the optic nerves and the spinal cord, it is increasingly recognized that NMOSD can involve any area of the CNS where aquaporin-4 is highly expressed. These other areas can include the hypothalamus and the circumventricular organs that surround the third and fourth ventricles, serving as osmoregulators. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is one of the most common causes of hyponatremia and has been associated with NMOSD due to these lesions. In this report, we present a case of a patient with known NMOSD, who presented with dizziness, fatigue, and generalized weakness and whose workup revealed hyponatremia in the setting of SIADH and hypothalamic demyelinating lesions. This case illustrates an atypical presentation of NMOSD and the importance of looking for syndromes, such as SIADH. This can guide diagnostic testing, such as getting thin MRI cuts through the hypothalamus and brainstem, as well as advanced management techniques such as immunotherapy.

Eosinophilic granulomatosis with polyangiitis as a rare cause of the syndrome of inappropriate antidiuretic hormone secretion

Eosinophilic granulomatosis with polyangiitis (EGPA, Churg-Strauss syndrome) is a rare multisystem necrotizing vasculitis that involves small- to medium-sized blood vessels. We report a rare case of syndrome of the inappropriate antidiuretic hormone (ADH) secretion (SIADH) secondary to EGPA. A 53-year-old man applied with complaints of pain in the large joints and morning stiffness in knee for 2 months. The patient had the history of impaired fasting glucose, asthma, nasal polyps, and urticaria. Physical examination revealed intrinsic muscle atrophy and weakness in the right hand. Peripheral eosinophil count was 9.78 × 109/L (0.02-0.5), erythrocyte sedimentation rate 39 mm/h (0-20), and C-reactive protein 5.77 mg/dL (0-0.5). Migratory ground-glass pulmonary opacities had been reported in previous chest computed tomography scans. Echocardiography revealed findings compatible with eosinophilic involvement. Electroneuromyographic evaluation showed acute distal axonal neuropathy of right ulnar nerve. EGPA was considered. Oral methylprednisolone treatment was initiated. Intravenous immunoglobulin (IVIG) and cyclophosphamide treatment and gradual tapering of oral steroids were planned. In 24-h urine analysis, sodium was 387 mEq, creatinine was 1156 mg, and volume was 3000 mL. When his medical records were investigated, it was observed that hyponatremia was present for nearly 2 years. While serum osmolality was 270, urine osmolality was 604 mOsm/kg H₂O. So, SIADH diagnosis was made. Fluid intake was restricted. Although the patient's sodium level did not return to normal, it rose up to 130 mEq/L. After second cycle of EGPA treatment (cyclophosphamide and IVIG), serum sodium was normal. There is only four other documented cases of SIADH associated with EGPA. We hypothesized that blood supply to the hypothalamus and/or posterior hypophysis might be affected from EGPA vasculitis. Here, in this case, with effective treatment of EGPA, SIADH was resolved which implies a causality between two conditions.

[A case of anti-myelin oligodendrocyte glycoprotein (MOG) antibody-related disease with human leukocyte antigen (HLA) positivity indicative of neuro-Sweet disease]

A 73-year-old man with a 5-day history of continuous hiccup, fever, and rapidly progressing paraplegia was admitted to our hospital. On admission, he exhibited dysarthria, complete paraplegia, and insentience of both lower limbs. Head and spine MRI showed abnormal, asymmetric lesions in the white matter, basal ganglia, and brainstem, and multiple spinal cord lesions. Test for serum anti-AQP4 antibody was negative. Evaluation of human leukocyte antigen (HLA)-B51 was negative; however, HLA-B54 was positive. Although skin lesions were absent, we considered neuro-Sweet disease and high-dose steroid therapy was initiated. The hiccup disappeared gradually, and he regained the ability to walk with a cane 30 days after the onset. Subsequently, the patient tested positive for serum anti-myelin oligodendrocyte glycoprotein (MOG) antibody. It is important to consider MOG antibody-related disease as potential diagnosis in patients exhibiting clinical features of neuro-Sweet disease except for the absence of skin lesions.

[Anti-NMDA receptor antibody-positive meningoencephalitis with SIADH and CNS demyelination: A case report]

After a 34-year-old female developed a headache and high fever, she was diagnosed with aseptic meningitis. On admission, neurological examinations revealed cerebellar limb ataxia, horizontal gaze paretic nystagmus, and pyramidal tract signs. Laboratory tests showed hyponatremia (129 mEq/l). Five days after admission, convulsions in the upper limbs due to the severe hyponatremia (108 mEq/l) were noted. In addition, serum antidiuretic hormone levels were markedly increased to 18.5 pg/ml. Brain MRI showed multiple small inflammatory lesions in the subcortical cerebral white matter, thalamus, and around the third ventricular diencephalic regions. Pulse corticosteroid treatment promptly improved her symptoms. Although tests for serum anti-aquaporin 4, anti-myelin oligodendrocyte glycoprotein, and anti-voltage-gated potassium channel antibodies were negative, cerebrospinal fluid samples tested positive for anti-N-methyl-D-aspartate (NMDA) receptor antibodies. Oral prednisolone administration was continued, but she developed paresthesia in her upper and lower extremities and gaze-evoked nystagmus three months after the first attack. MRI showed that the previously observed high-intensity regions were decreased, but a new area of high intensity was observed in ventral regions through the lower midbrain to the pons. Because pulse corticosteroid treatment was again effective, we continued the oral prednisolone treatment. This case presented none of the characteristic symptoms of anti-NMDA receptor antibody encephalitis during the clinical course other than repeated demyelinating encephalitis and severe syndrome of inappropriate antidiuretic hormone secretion (SIADH). Additional clinical observations are needed to better understand the underlying pathology of the NMDA receptor antibodies in the cerebrospinal fluid in this case.

Syndrome of inappropriate antidiuretic hormone secretion associated with seronegative neuromyelitis optica spectrum disorder

The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a potential cause of hyponatremia of the central nervous system (CNS). Although SIADH has been reported to be associated with many other central nervous disorders, its association with neuromyelitis optica (NMO) or NMO spectrum disorders are rare. NMO is a demyelinating disorder characterized by optic neuritis and transverse myelitis. Aquaporin-4 (AQP4), which is the target antigen for a NMO autoantibody, is the predominant CNS water channel. However, some NMO patients show seronegative AQP4 antibody results. The spectrum of NMO has been changed, and new findings about the disease have been reported. Here, we report a case of seronegative NMO spectrum disorder associated with SIADH.

Syndrome of inappropriate antidiuretic hormone secretion in patients with aquaporin-4 antibody

The objective of this study was to analyze the frequency of syndrome of inappropriate antidiuretic hormone secretion (SIADH) in patients with positive aquaporin-4 (AQP4) antibodies and evaluate the relationship between SIADH and hypothalamic lesions in patients with NMO and NMO spectrum disorder (NMOSD). AQP4 antibodies were tested by an indirect immunofluorescence assay employing HEK-293 cells transfected with recombinant human AQP4. Clinical data of patients were analyzed retrospectively. In total, 192 patients with AQP4 antibodies were certified, of which 41 patients (21.4 %) were included in the present study. Six patients (14.6 %, 6/41) met the criteria of SIADH, of which hyponatremia was mild in one patient, and severe in five. Five patients experienced confusion or decreased consciousness. Four patients were diagnosed with NMO and two were diagnosed with recurrent optic neuritis. Magnetic resonance imaging showed 11 of 41 patients (26.8 %) had hypothalamic lesions. All patients with SIADH had hypothalamic abnormalities. Hyponatremia resolved in all patients after intravenous methylprednisolone and intravenous immunoglobulin therapy. SIADH is not rare in patients with NMO/NMOSD, especially in patients with lesions close to the hypothalamus.

A rare case of hyponatremia from a hypothalamic lesion in a patient with multiple sclerosis

The syndrome of inappropriate antidiuretic hormone secretion (SIADH) can occur from a variety of neurologic and systemic processes; however, it has rarely been seen in multiple sclerosis (MS). We report a case of SIADH in a patient with MS and compare it with previously reported English-only cases. A 32-year-old woman experienced generalized fatigue followed by confusion and was found to have profound hyponatremia. Her work-up demonstrated SIADH secondary to a discrete enhancing hypothalamic lesion. Despite the seldom occurrence of SIADH in MS, hypothalamic lesions are more common than appreciated and should be considered in patients presenting with hyponatremia or endocrinopathy symptoms.

[Case of neuromyelitis optica spectrum disorder associated with central pontine and extrapontine myelinolysis preceded by syndrome of inappropriate antidiuretic hormone secretion]

A 36-year-old woman complained of general malaise. She presented with hyponatremia and plasma osmotic pressure was lower than urinary osmotic pressure. In addition, serum antidiuretic hormone level was higher than the measurement sensitivity. She was diagnosed with the syndrome of inappropriate antidiuretic hormone secretion (SIADH). She fell into a coma despite correction of serum sodium level. Brain magnetic resonance imaging (MRI) revealed high signal intensities in the cerebral cortex, striatum, thalamus, hypothalamus, midbrain, and pons in fluid-attenuated inversion recovery images. Spinal MRI revealed a longitudinally extending lesion in the cervical cord. Serum sample was positive for anti-aquaporin-4 antibody, supporting the diagnosis of neuromyelitis optica spectrum disorder (NMOSD) combined with central pontine and extrapontine myelinolysis. In patients with NMOSD, the immune reaction can gradually cause destructive changes of the hypothalamus and lead to unstable ADH secretion in the absence of immunomodulatory treatment.

Acute combined central and peripheral demyelination showing anti-aquaporin 4 antibody positivity

Neuromyelitis optica spectrum disorder (NMOSD) is characterized by optic neuritis or transverse myelitis with anti-aquaporin 4 (AQP4) antibodies (1). We herein present the case of a patient with NMOSD who also was affected with peripheral neuropathy. A 58-year-old woman developed gait disturbance and sensory impairment in the lower limbs. She exhibited longitudinally extensive transverse myelitis with anti-AQP4 antibodies. Nerve conduction studies showed demyelinating changes. Laboratory findings showed hepatitis-C virus (HCV) infection. Her peripheral neuropathy improved after immunotherapy. There have been no previous reports of NMO or NMOSD associated with neuropathy. The HCV infection or undetermined humoral factors other than the anti-AQP4 antibodies may have caused her peripheral neuropathy.

[Hypothalamic involvement in multiple sclerosis]

Hypothalamic involvement is a rare condition in patients with multiple sclerosis (MS). We report two patients with a long history of MS who presented with severe acute hypothermia with associated thrombocytopenia and elevated transaminase levels. Several cases of hypothermia or hyperthermia in patients with MS have been reported in the literature. They could be linked with hypothalamic lesions, in particular in the pre-optic area. However, other anatomical locations seem to be involved in thermoregulation and can be affected by MS. Besides, some cases of syndrome of inappropriate antidiuretic hormone secretion have been reported in patients with MS. Finally, some sleep disorders, particularly hypersomnia or narcolepsy, could be related to hypothalamic lesions, through the fall in hypocretin-1 in the cerebrospinal fluid. Hypocretin-1 is a neuropeptide that is secreted by some hypothalamic cells. It plays a role in the sleep-awake rhythm. We report one patient with narcolepsy and cataplexy before the first symptoms of MS appeared. Hypothalamic signs are rare in MS. However, several series of autopsies have shown a high frequency of demyelinating lesions in the hypothalamic area. Among these lesions, the proportion of active lesions seems elevated. Yet only few of them have a clinical or biological translation such as thermoregulation dysfunction, sleep disorders or natremia abnormalities. Thus, it seems unlikely that inflammatory hypothalamic lesions alone, even when bilateral, could be the explanation of these signs. A sufficient number of inflammatory demyelinating lesions, which we can observe in patients with a long history of MS and an already severe disability, is probably necessary to develop such a rare symptomatology. Hypothalamic signs might be a factor of poor prognosis for the disease course and progression of the disability.

[Neuromyelitis optica with syndrome of inappropriate secretion of antidiuretic hormone and hypersomnia associated with bilateral hypothalamic lesions: a case report]

A 31-year-old woman with a 5-year history of recurrent optic neuritis and encephalomyelitis underwent repeated steroid therapy. She developed general malaise and fever in October 2009. Laboratory tests revealed marked reduction in serum Na (106 mEq/L). Because the plasma osmotic pressure was lower than the urinary osmotic pressure and the serum antidiuretic hormone (ADH) level was elevated, she was diagnosed with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Magnetic resonance imaging (MRI) revealed high signal intensities on symmetrical T2 weighted and fluid attenuated inversion recovery (FLAIR) images of both sides of the hypothalamus. The serum samples tested positive for the antibody to aquaporin-4 (AQP4). Previously conducted cervical MRI had revealed a longitudinally extending lesion in the cervical cord, and brain MRI had revealed brainstem lesions. We diagnosed the patient with neuromyelitis optica (NMO) according to the revised diagnostic criteria for NMO proposed by Wingerchuk in 2006. Furthermore, she complained of excessive daytime sleepiness. The concentration of orexin in the cerebrospinal fluid was mildly reduced and the orexin levels returned to normal when her sleepiness decreased. ADH and orexin neurons localized in the hypothalamus; hence, we considered the above-mentioned symptoms to be caused by bilateral hypothalamic lesions.

Anti-aquaporin-4 antibody-positive neuromyelitis optica presenting with syndrome of inappropriate antidiuretic hormone secretion as an initial manifestation

The distribution of neuromyelitis optica (NMO)-characteristic brain lesions corresponds to sites of high aquaporin-4 (AQP4) expression, and the brainstem and hypothalamus lesions that express high levels of AQP4 protein are relatively characteristic of NMO. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is one of the important causes of hyponatremia and results from an abnormal production or sustained secretion of antidiuretic hormone (ADH). SIADH has been associated with many clinical states or syndromes, and the hypothalamic-neurohypophyseal system regulates the feedback control system for ADH secretion. We report the case of a 63-year-old man with NMO, whose initial manifestation was hyponatremia caused by SIADH. Retrospective analysis revealed that the serum anti-AQP4 antibody was positive, and an MRI scan showed a unilateral lesion in the hypothalamus. SIADH recovered completely with regression of the hypothalamic lesion. As such, NMO should even be considered in patients who develop SIADH and have no optic nerve or spinal cord lesions but have MRI-documented hypothalamic lesions.

Recognition of acute illness in people with chronic neurological disability

Coincidental acute illness is common in patients with chronic progressive or stable neurological disability. Although the presentation of acute illness in these patients is often similar to that in people without pre-existing disability, sometimes it may be atypical. In addition, an adequate medical history is often difficult to obtain in patients with advanced neurological disease, for example because of the presence of aphasia, severe dysarthria, or cognitive impairment. In these circumstances early and accurate diagnosis of acute medical and surgical emergencies requires both clinical acumen and a high index of suspicion. The aim of this article is to describe the main atypical manifestations of acute illness in patients with chronic disabling neurological disorders.

Syndrome of inappropriate antidiuresis associated with multiple sclerosis

Even though many disorders of the nervous system have been reported to be associated with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), the association of this syndrome with multiple sclerosis is extremely rare. We describe a patient with multiple sclerosis who developed SIADH and hyponatremia.

Idiopathic hypothalamic dysfunction with dilated unresponsive pupils: report of two cases

Idiopathic hypothalamic dysfunction is a rare but well-defined entity in childhood characterized by adipsia-hypernatremia, obesity, poor thermoregulation, and disturbance of pituitary function. Two cases of idiopathic hypothalamic dysfunction are described. There are 10 previously reported cases in the literature, and the clinical features are compared. The present cases are unique in that the patients also had bilaterally dilated unresponsive pupils. In the first case, there was no demonstrable pathology at autopsy; in the second case, lymphocytic infiltration of the hypothalamus and midbrain associated with neuronal loss was present at autopsy. Possible etiologies are discussed.