Superficial siderosis of the central nervous system: secondary progression despite successful surgical treatment, mimicking amyotrophic lateral sclerosis. Case report and review

Duropathy as a rare motor neuron disease mimic: from bibrachial amyotrophy to infratentorial superficial siderosis

BACKGROUND

Bibrachial amyotrophy associated with an extradural CSF collection and infratentorial superficial siderosis (SS) are rare conditions that may occasionally mimic ALS. Both disorders are assumed to be due to dural tears.

CASE PRESENTATION

A 53-year-old man presented with a 7-year history of slowly progressive asymmetric bibrachial amyotrophy. Initially, a diagnosis of atypical motor neuron disease (MND) was made. At re-evaluation 11 years later, upper limb wasting and weakness had further progressed and were accompanied by sensorineural hearing loss. MRI of the brain and spine demonstrated extensive supra- and infratentorial SS (including the surface of the whole spinal cord) as well as a ventral longitudinal intraspinal fluid collection (VLISFC) extending along almost the entire thoracic spine. Osteodegenerative changes were observed at C5-C7 level, with osteophytes protruding posteriorly. The bony spurs at C6-C7 level were hypothesized to have lesioned the dura, causing a CSF leak and thus a VLISFC. Review of the MRI acquired at first evaluation showed that the VLISFC was already present at that time (actually beginning at C7 level), whereas the SS was not. 19 years after the onset of upper limb weakness, the patient additionally developed parkinsonism. Response to levodopa, brain scintigraphy with 123I-ioflupane and brain MRI with nigrosome 1 evaluation were consistent with idiopathic Parkinson's disease (PD). On the latest follow-up 21 years after symptom onset, the VLISFC was unchanged, as were upper arm weakness and wasting.

CONCLUSIONS

Based on the long-term follow-up, we could establish that, while the evidence of the VLISFC was concomitant with the clinical presentation of upper limb amyotrophy and weakness, the radiological signs of SS appeared later. This suggests that SS was not per se the cause of the ALS-like clinical picture, but rather a long-term sequela of a dural leak. The latter was instead the causative lesion, giving rise to a VLISFC which compressed the cervical motor roots. Dural tears can actually cause several symptoms, and further studies are needed to elucidate the pathophysiological correlates of "duropathies". Finally, as iron metabolism has been implicated in PD, the co-occurrence of PD with SS deserves further investigation.

Acute to Chronic Variants in the Imaging Spectrum of Superficial Siderosis: Case Series and Literature Review

Superficial siderosis is a rare neurodegenerative disease, related to the deposition of hemosiderin in the central nervous system secondary to recurrent bleeding into subarachnoid space and results in chronic or progressively neurological deterioration. It tends to be due to chronic slow haemorrhages in the setting of previous cranio-spinal trauma or neurosurgery that had been done decades ago. It is important to diagnose the disease as soon as possible because if left untreated it can cause progressive ataxia and deafness, which will require surgical intervention. There are three types of superficial siderosis: Type 1 (the classical infratentorial variant), which is characterised by symmetric deposits in the cerebellum, brain stem, or cranio-cervical junction; type 2 (secondary infratentorial subdural hygroma), an acquired non-communicating secondary supratentorial subdural hygroma (SSDH) subtype manifesting as limited asymmetric fluid collections related to a single intracranial bleeding event and supratentotrial superficial siderosis that represents deposition along cerebral convexities usually due previous hemorrhagic episodes. A singular form is "acute superficial siderosis syndrome," progressing much more rapidly than pure superficial siderosis and due to recurrent haemorrhages. The present case series is intended to describe and illustrate acute and chronic manifestations of superficial siderosis, emphasizing its distinct imaging appearances facilitating early recognition, leading to prompt management.

Bibrachial amyotrophy as a rare manifestation of intraspinal fluid collection: a case report and systematic review

INTRODUCTION

Intraspinal cerebrospinal fluid (CSF) collection has been reported as a rare cause of lower motor neuron (LMN) disorder. We report a case of bibrachial diplegia associated with intraspinal CSF collection and perform a systematic literature review.

PATIENT AND METHODS

A 52-year-old man developed a bibrachial amyotrophy over 6 years, confirmed by the presence of cervical subacute neurogenic changes at electromyography (EMG). Brain magnetic resonance imaging (MRI) revealed cerebral siderosis, while spine MRI showed a ventral longitudinal intraspinal fluid collection (VLISFC) from C2 to L2. No CSF leakage was localized at myelography; a conservative treatment was chosen. We searched for all published cases until 30th April 2023 and extrapolated data of 44 patients reported in 27 publications.

RESULTS

We observed a male predominance, a younger disease onset compared to amyotrophic lateral sclerosis, and a quite long disease duration, highlighting a slow disease progression. LMN signs were more frequently bilateral, mostly involving C5-C6 myotomes. Around 61% of patients presented additional symptoms, but only three referred to a history of headache. Accordingly, CSF opening pressure was mostly normal. Spinal MRI revealed the presence of VLISFC and in some cases myelomalacia. EMG patterns displayed both chronic and subacute neurogenic change in the cervical region. The disease course mainly depended on the treatment choice, which was mostly represented by a surgical approach when a specific dural defect was detected by imaging.

CONCLUSION

Bibrachial diplegia due to VLISFC can be a treatable cause of focal amyotrophy and presents some clinical and radiological "red flags" which cannot be missed by a clinical neurologist.

Closure of a dural defect as a cause of superficial siderosis: does early dural repair lead to a better outcome? Illustrative case

BACKGROUND

Superficial hemosiderosis (SS) of the central nervous system is a rare condition that is caused by chronic, repeated hemorrhage into the subarachnoid space. The subsequent deposition of hemosiderin in the brain and spinal cord causes neurological deterioration. In this report, the authors describe a repair procedure for SS associated with a dural defect in the thoracic spine.

OBSERVATIONS

A 75-year-old man presented with tinnitus symptoms that began about 1 year prior. Subsequently, his hearing loss progressed, and he gradually became unsteady on walking. Magnetic resonance imaging (MRI) of the head showed diffuse hemosiderin deposition on the surface of the cerebellum. Thoracic MRI showed ventral cerebrospinal fluid leakage of T2-7, and computed tomography myelography showed leakage of contrast medium that appeared to be a dural defect. Dural closure was successful, and MRI showed decreased fluid collection ventral to the dura. The patient's symptoms of wobbliness on walking and tinnitus improved dramatically from the postoperative period.

LESSONS

Dural abnormalities of the spine must always be considered as one of the causes of SS. Early dural closure is an effective means of preventing the progression of symptoms.

Successful endoscopic identification of the bleeding source in the ventral dura of the cervical spine in a case of superficial siderosis

The authors report on the case of a 65-year-old man suffering progressive gait disturbance and hearing impairment due to superficial siderosis (SS). According to the literature, repeated hemorrhage into the subarachnoid space causes SS; however, the bleeding source remains unknown in half of SS patients. In the presented case, preoperative MRI revealed a fluid-filled intraspinal cavity extending from C2 to T8 with a dural defect at the ventral C7 level. During surgery, the dural defect was seen to connect to the intraspinal cavity filled with xanthochromic fluid. Importantly, endoscopic observation verified that the rupture of fragile bridging veins in the cavity was the definite bleeding source. Postoperative MRI confirmed disappearance of the intraspinal cavity, and the patient's symptoms gradually improved. The use of endoscopy helped to establish the diagnosis and led to definite treatment. Fragile bridging veins in the fluid-filled interdural layers were novelly verified as a bleeding source in SS. Recognizing this phenomenon is important since it can establish closure of the dural defect as a definite treatment in SS with an intraspinal cavity.

Ventral Longitudinal Intraspinal Fluid Collection in Patients with Cervical Disc Herniation: A Report of Two Cases

We encountered two cases of cervical disc herniation, wherein cerebrospinal fluid collection in the ventral epidural space between the cervical spine and the thoracic spine was noted. The patients, two women aged 71 and 43 years, were diagnosed with cervical disc herniation and underwent anterior cervical discectomy and fusion. Unexpected cerebrospinal fluid leakage was observed prior to exposure of the dura mater. Notably, the dura mater was intact following the removal of the herniated disc in both cases. No cerebrospinal fluid leakage symptoms were observed, and relief from the neurological symptoms related to the cervical disc herniation was observed in both cases following the surgery. Findings of preoperative magnetic resonance imaging and computed tomography myelography were carefully reviewed, retrospectively. Both patients presented with similar features including expansion of cerebrospinal fluid collection in the ventral epidural space between the cervical spine and the thoracic spine. These observed features were similar to those of superficial siderosis, which is a form of duropathy—a disease caused by dural defects. Therefore, the patients in this case study might have a subclinical duropathy with associated cervical disc herniation.

Superficial Siderosis of the Central Nervous System Originating from the Thoracic Spine: A Case Report

Superficial siderosis of the central nervous system(SSCNS) is a rare disease characterized by hemosiderin deposition on the surface of the central nervous system. We report a case of SSCNS originating from the thoracic spine, presenting with neurological deficits including, sensorineuronal hearing loss, ataxia, and corticospinal and dorsal column tract signs. The patient underwent dural repair with an artificial dural patch. Clinical findings were elicited by neurological examination, imaging studies, and intraoperative findings, and these were addressed through literature review.

Superficial siderosis of the central nervous system: A case report

Superficial siderosis of the central nervous system (SSCNS) is a rare syndrome resulting from hemosiderin deposits in neuronal tissues close to the cerebrospinal fluid. SSCNS is characterized by sensorineural deafness, cerebellar ataxia and signs of pyramidal tract dysfunction. The present study describes a patient with SSCNS that did not suffer from hearing loss, which is the most common symptom of SSCNS. The patient was a 48-year-old male, presenting with dizziness, ataxia and slurred speech. The patient’s ataxia was characterized by dizziness, nystagmus, dysarthria, abnormal finger-nose pointing and heel-knee-shin tests and a positive Chaddock sign. The patient had suffered from a pontine hemorrhage two years prior to the study. Audiometric tests showed normal hearing during the hospital stay and at the two-month follow-up examination. The diagnosis of SSCNS was made based on magnetic resonance images, which showed areas of linear hypointensity on the surface of the pons with mild cerebellar atrophy. However, a long-term follow-up is required to monitor the hearing of the patient. Improved understanding of SSCNS is important for clinicians to identify SSCNS patients who present without typical clinical symptoms.

Spinal manifestations of spontaneous intracranial hypotension

Object

The goal of the study was to elucidate the spinal manifestations of spontaneous intracranial hypotension.

Methods

The authors reviewed the medical records and imaging studies of 338 consecutive patients with spontaneous intracranial hypotension who were evaluated at their institution between 2001 and 2010.

Results

Twenty patients (6%; mean age 35.8 [range 16 to 60 years]; 5 males and 15 females) had convincing signs or symptoms referable to the spinal cord or spinal nerve roots. The spinal manifestations consisted of radiculopathy in 11 patients (unilateral in 8 and bilateral in 3), myelopathy in 8 patients, and bibrachial amyotrophy in 1 patient. The cervical spine was involved in 12 patients, the thoracic spine in 5, and the lumbosacral spine in 3. The spinal symptoms were positional in only 3 patients. The spinal manifestations occurred around the time of the headache onset in 16 patients, and months to years after the positional headache had resolved in 4 patients. A large extrathecal CSF collection causing compression of the spinal cord or nerve root was responsible for the spinal manifestations in the majority of patients. Treatment of the spinal CSF leak resulted in resolution of the spinal manifestations along with the headache, except for those in the patient with bibrachial amyotrophy.

Conclusions

Spinal manifestations are uncommon in cases of spontaneous intracranial hypotension, occurring in about 6% of patients, but myelopathy and radiculopathy involving all spinal segments do occur. Unlike the headache, the spinal manifestations usually are not positional and are caused by mass effect from an extradural CSF collection.

Superficial siderosis and anticoagulation therapy: different presentations, different outcomes

Superficial siderosis is a potentially manageable neurodegenerative disorder, caused by chronic subarachnoid haemorrhage and iron deposition along the central nervous system surfaces. Association with oral anticoagulant therapy is well known, but its definite role as a causative agent is yet to be clarified. Two Caucasian women, both under long-term oral anticoagulation: a 74 year old woman with slowly progressive hearing loss and mild cerebellar ataxia; a 72 year old woman suffering from behavioural changes, rapidly progressive cognitive decline and latter developing paraparesis. Magnetic resonance imaging showed striking hypointensities along the surfaces of cerebellum, brainstem, frontotemporal cortices, spinal cord, and lumbar arachnoid therefore suggesting superficial siderosis. No specific bleeding source was found in any of the patients. Anticoagulation could not be stopped in the first patient due to a mechanic valve and slowly progressive worsening occurred. In contrast, for the second patient anticoagulation withdrawal was feasible and marked motor and cognitive improvement ensued. Superficial siderosis is associated with unvarying progression, mostly when no direct source of bleeding is identified. Nonetheless, we verified striking motor and cognitive improvement after anticoagulants withdrawal in one of the patients. This may reinforce the need to consider such modifiable factor in future patient management.

Three cases of superficial siderosis of the central nervous system and review of the literature

Superficial siderosis of the central nervous system results from chronic or intermittent hemorrhage into the subarachnoid space that causes hemosiderin deposition in subpial layers of the brain and the spinal cord leading to neuronal damage. Patients present with progressive and debilitating symptoms that typically include adult-onset slowly progressive cerebellar gait ataxia and sensorineural hearing impairment. Regardless of extensive investigations, the origin of the hemorrhage is often not clear. Because of the good availability of magnetic resonance imaging, asymptomatic cases of superficial siderosis of the central nervous system are increasingly discovered. SS cases are increasingly reported in the literature. We present three new cases. The etiology, pathogenesis, clinical features, and treatment options of SS are reviewed.

Chronic cerebellar hemorrhage in spontaneous intracranial hypotension: association with ventral spinal cerebrospinal fluid leaks

Object

Spontaneous intracranial hypotension is an important cause of new-onset daily persistent headache. Cerebellar hemorrhage has been identified as a possible feature of spontaneous intracranial hypotension. The authors reviewed the MR imaging studies from a group of patients with spontaneous intracranial hypotension to assess the presence of cerebellar hemorrhage.

Methods

Medical records and radiological images were reviewed in 262 cases involving patients with spontaneous intracranial hypotension who had undergone MR imaging of the brain as well as spinal imaging.

Results

Chronic cerebellar hemorrhages were found in 7 (2.7%) of the 262 patients with spontaneous intracranial hypotension. These hemorrhages were found in 7 (19.4%) of the 36 patients with a ventral spinal CSF leak and in none of the 226 patients who did not have such a CSF leak (p < 0.0001). The degree of hemosiderin deposits was variable, ranging from mild involvement of the cerebellar folia to widespread superficial siderosis. Only the 1 patient with superficial siderosis had symptoms due to the hemorrhages. The time period between the onset of symptoms due to spontaneous intracranial hypotension and MR imaging examination was significantly longer in those patients with cerebellar hemorrhage than in those with a ventral spinal CSF leak and no evidence for cerebellar hemorrhage (mean 19.6 years vs 2.3 months, p < 0.0001).

Conclusions

Chronic cerebellar hemorrhage should be included among the manifestations of spontaneous intracranial hypotension. The severity is variable, but the hemorrhage generally is asymptomatic. The underlying spinal CSF leak is ventral and mostly of long duration.