Spinal dementia: Don't miss it, it's treatable.

BACKGROUND & PURPOSE: Around 5% of dementia patients have a treatable cause. To estimate the prevalence of two rare diseases, in which the treatable cause is at the spinal level. METHODS: A radiology information system was searched using the terms CT myelography and the operation and classification system (OPS) code 3-241. The clinical charts of these patients were reviewed to identify patients with a significant cognitive decline. RESULTS: Among 205 patients with spontaneous intracranial hypotension (SIH) and proven CSF leaks we identified five patients with a so-called frontotemporal brain sagging syndrome: Four of those had CSF venous fistulas and significantly improved by occluding them either by surgery or transvenous embolization. Another 11 patients had infratentorial hemosiderosis and hearing problems and ataxia as guiding symptoms. Some cognitive decline was present in at least two of them. Ten patients had ventral dural tears in the thoracic spine and one patient a lateral dural tear at C2/3 respectively. Eight patients showed some improvement after surgery. DISCUSSION: It is mandatory to study the (thoracic) spine in cognitively impaired patients with brain sagging and/ or infratentorial hemosiderosis on MRI. We propose the term spinal dementia to draw attention to this region, which in turn is evaluated with dynamic digital subtraction and CT myelography.

Brain Sagging Dementia.

PURPOSE OF REVIEW: Brain sagging dementia (BSD) is a rare but devastating form of early-onset dementia characterized by intracranial hypotension and behavioral changes resembling behavioral variant frontotemporal dementia. This review aims to provide a comprehensive overview of BSD, highlighting its pathomechanism, diagnostic tools, and available treatment options. RECENT FINDINGS: BSD exhibits a complex clinical manifestation with insidious onset and gradual progression of behavioral disinhibition, apathy, inertia, and speech alterations. Additionally, patients may exhibit brainstem and cerebellar signs such as hypersomnolence and gait disturbance. Although headaches are common, they may not always demonstrate typical orthostatic features. Recent radiological advances have improved the detection of CSF leaks, enabling targeted treatment and favorable outcomes. Understanding the pathomechanism and available diagnostic tools for BSD is crucial for a systematic approach to timely diagnosis and treatment of this reversible form of early-onset dementia, as patients often endure a complex and lengthy clinical course.

The anatomy of vascular compression in trigeminal neuralgia.

The etiological basis of trigeminal neuralgia (TN) is unknown but vascular (arterial and venous) compression of the trigeminal nerve roots has emerged as the likely cause in most cases. Here we examine the evidence for the "brain sagging/arterial elongation hypothesis" with reference to the cerebral arteries and veins believed to cause the compression. Most often implicated are the superior cerebellar artery, the anterior and posterior inferior cerebellar arteries, and the superior petrosal vein including several of its tributaries. The reviewed data suggest that the theoretical support for a vascular compressive etiology of TN is weak, albeit the surgical outcome data are relatively convincing.

Movement Disorders in Brain Sagging Syndrome Due To Spontaneous Intracranial Hypotension: A Review.

Background: Spontaneous intracranial hypotension (SIH), a treatable condition that stems from spinal leakage of cerebrospinal fluid, usually presents with orthostatic headache, nausea, vomiting, dizziness, and tinnitus. A subset of patients, especially those with sagging of brain structures ("brain sagging syndrome"), develop several movement abnormalities. As SIH is treatable with epidural blood patch (EBP), movement disorders neurologists should be familiar with this syndrome. Method: The authors performed a literature search in PubMed in July 2024 using the Boolean phrase- (("Brain sagging")OR("Intracranial hypotension"))AND(((((((((("Movement disorders")OR("Involuntary movements"))OR("Tremor"))OR("Dystonia"))OR("Chorea"))OR("Ballismus"))OR("Myorhythmia"))OR ("Tic"))OR("Ataxia"))OR("Parkinsonism")). Result: We tabulated 21 case reports/series that highlighted the presence of movement disorders. The most reported phenomenology is gait unsteadiness. While it usually emerges in the background of the classic SIH symptoms, rarely, patients may present with isolated gait dysfunction. Tremor is the second most reported phenomenology with postural and kinetic tremor being the common subtypes. Holmes tremor has also been reported in SIH. Other reported phenomenologies are parkinsonism, chorea, and dystonia. One study reported a unique phenomenology i.e. compulsive repetitive flexion and breath holding in 35.3% of the patients. In majority of the patients, EBP resulted in substantial clinical and radiological improvement. Discussion: Brain sagging syndrome due to SIH may present with a wide range of movement disorders. Mechanical distortion of the posterior fossa and subcortical structures result in the emergence of such movement abnormality. SIH adds to the list of conditions that result in "treatable movement disorders." Therefore, movement disorders neurologists should be versed with the diagnosis and clinical features of this condition.

Why can spontaneous intracranial hypotension cause behavioral changes? A case report and multimodality neuroimaging comparison with frontotemporal dementia.

Frontotemporal Brain Sagging Syndrome (FBSS) is a rare condition characterized by the presence of spontaneous intracranial hypotension associated with behavioural disturbances mimicking the behavioural variant of Frontotemporal dementia (bvFTD). It has been suggested that behavioural symptoms are caused by damage to the connectivity of the frontal lobes due to the brain sagging. However, no studies have directly explored brain connectivity in patients with FBSS. Here, we report a new case of FBSS with persistent behavioural disturbances, whom we compared to 20 patients with bvFTD and to 13 cognitively healthy controls using Magnetic Resonance Imaging (MRI). We explored differences related to grey matter (GM) volume with voxel-based morphometry, functional connectivity with seed-based analysis, and white matter (WM) microstructural integrity with tract-based spatial statistics. We found that the FBSS patient, like the controls, had greater GM volume relative to the bvFTD patients. Moreover, the FBSS patient had greater functional connectivity from a left inferior frontal gyrus seed than both the bvFTD patients and healthy controls groups in dorsolateral frontal areas. Like the bvFTD group the FBSS patient had decreased WM integrity relative to the controls, especially in the posterior part of the corpus callosum, and the magnitude of these abnormalities correlated with measures of apathy across the FBSS and bvFTD patients. Our results suggest that behavioural changes associated with SIH are mainly due to altered WM connectivity.

A case of spontaneous intracranial hypotension in a 45-year-old male with headache, behavior changes and altered mental status.

Spontaneous intracranial hypotension is a rare disease that results from low cerebrospinal fluid (CSF) volume caused by leakage of CSF from the spine in the absence of lumbar puncture, spine surgery, or intervention. The most common presentation is the headache that is usually but not invariably orthostatic. The underlying pathology is a CSF leak resulting from dural weakness involving the nerve root sleeves, ventral dural tears associated with calcified disc herniations, or CSF venous fistula. In severe cases, neuropsychiatric symptoms and changes in mental status may develop. Some case reports also mention gait disturbances, slurred speech, and urinary incontinence. The constellation of neuropsychiatric symptoms similar to behavior variant frontotemporal dementia in the presence of "brain sag" on MRI is known as frontotemporal brain sagging syndrome, first described by Wicklund et al. (4). The disease presents a diagnostic challenge to the primary care physicians, who are the first to see these patients. Brain and spine imaging is key to diagnoses but requires a high index of suspicion, as very rarely are all classic findings of intracranial hypotension present in the same patient. Here we discuss a case of spontaneous intracranial hypotension in a 45-year-old male patient who presented with headache, drowsiness, incoherent speech, behavior symptoms, and altered mental status.

The reversible impairment of behavioral variant frontotemporal brain sagging syndrome: Challenges and opportunities.

Introduction: Due to loss of brain buoyancy, spontaneous spinal cerebrospinal fluid (CSF) leaks cause orthostatic headaches but also can cause symptoms indistinguishable from behavioral variant frontotemporal dementia (bvFTD) due to severe brain sagging (including the frontal and temporal lobes), as visualized on brain magnetic resonance imaging. However, the detection of these CSF leaks may require specialized spinal imaging techniques, such as digital subtraction myelography (DSM). Methods: We performed DSM in the lateral decubitus position under general anesthesia in 21 consecutive patients with frontotemporal dementia brain sagging syndrome (4 women and 17 men; mean age 56.2 years [range: 31-70 years]). Results: Nine patients (42.8%) were found to have a CSF-venous fistula, a recently discovered type of CSF leak that cannot be detected on conventional spinal imaging. All nine patients underwent uneventful surgical ligation of the fistula. Complete or near-complete and sustained resolution of bvFTD symptoms was obtained by all nine patients, accompanied by reversal of brain sagging, but in only three (25.0%) of the twelve patients in whom no CSF-venous fistula could be detected (P = 0.0011), and who were treated with non-targeted therapies. Discussion: Concerns about a spinal CSF leak should not be dismissed in patients with frontotemporal brain sagging syndrome, even when conventional spinal imaging is normal. However, even with this specialized imaging the source of the loss of spinal CSF remains elusive in more than half of patients.

Differentiation of Chiari malformation type 1 and spontaneous intracranial hypotension using objective measurements of midbrain sagging.

OBJECTIVE: Chiari malformation type 1 (CM-1) and spontaneous intracranial hypotension (SIH) are causes of headache in which cerebellar tonsillar ectopia (TE) may be present. An accurate method for differentiating these conditions on imaging is needed to avoid diagnostic confusion. Here, the authors sought to determine whether objective measurements of midbrain morphology could distinguish CM-1 from SIH on brain MRI. METHODS: This is a retrospective case-control series comparing neuroimaging in consecutive adult subjects with CM-1 and SIH. Measurements obtained from brain MRI included previously reported measures of brain sagging: TE, slope of the third ventricular floor (3VF), pontomesencephalic angle (PMA), mamillopontine distance, lateral ventricular angle, internal cerebral vein-vein of Galen angle, and displacement of iter (DOI). Clivus length (CL), an indicator of posterior fossa size, was also measured. Measurements for the CM-1 group were compared to those for the entire SIH population (SIHall) as well as a subgroup of SIH patients with > 5 mm of TE (SIHTE subgroup). RESULTS: Highly significant differences were observed between SIHall and CM-1 groups in the following measures: TE (mean ± standard deviation, 3.1 ± 5.7 vs 9.3 ± 3.5 mm), 3VF (-16.8° ± 11.2° vs -2.1° ± 4.6°), PMA (44.8° ± 13.1° vs 62.7° ± 9.8°), DOI (0.2 ± 4.1 vs 3.8 ± 1.6 mm), and CL (38.3 ± 4.5 vs 44.0 ± 3.3 mm; all p < 0.0001). Eight (16%) of 50 SIH subjects had TE > 5 mm; in this subgroup (SIHTE), a cutoff value of < -15° for 3VF and < 45° for PMA perfectly discriminated SIH from CM-1 (sensitivity and specificity = 1.0). DOI showed perfect specificity (1.0) in detecting SIH among both groups. No subjects with SIH had isolated TE without other concurrent findings of midbrain sagging. CONCLUSIONS: Measures of midbrain sagging, including cutoff values for 3VF and PMA, discriminate CM-1 from SIH and may help to prevent misdiagnosis and unnecessary surgery.

Spontaneous Intracranial Hypotension - A Dilemma.

BACKGROUND: Spontaneous intracranial hypotension (SIH) is a highly misdiagnosed and underdiagnosed disorder. OBJECTIVE: Update evaluation and treatment of spontaneous intracranial hypotension. METHODS AND MATERIAL: Narrative review. RESULTS: Traditionally, SIH is diagnosed when a headache has developed spontaneously and in temporal relation to a CSF leak (evident on imaging) and/or CSF hypotension (lumbar puncture opening pressure <60 mm CSF). However, lumbar puncture is not mandatorily required to diagnose SIH. Besides headache, other symptoms such as nausea/vomiting in 50.6%, neck pain/stiffness in 33%, tinnitus in 19%, dizziness in 14%, hearing disturbances in 10.7%, followed by visual disturbances, vertigo, back pain, and cognitive symptoms may be present. In suspected cases of SIH, brain and spine should be evaluated with MRI. Dynamic computerized tomographic myelography is required to demonstrate the site of spinal CSF leak. Epidural blood patch (EBP) is a minimally invasive treatment for spontaneous intracranial hypotension (SIH) refractory to medical management and provides symptomatic relief in up to 90% of patients even in patients with bilateral subdural hematomas. The CSF-venous fistulas do not respond well to EBP, and the most definitive curative treatment is the surgical closure of the fistula. CONCLUSIONS: The SIH is a distinct entity and requires a high index of suspicion for diagnosis. A post-contrast MRI should be included for evaluation of headaches. Spinal MRI should be done to demonstrate the site of leak. Epidural blood patch therapy is the most effective treatment of SIH. Most SDHs associated with SIH do not require treatment.

Frontotemporal brain sagging syndrome: Craniospinal hypovolemia secondary to a T6-T7 cerebrospinal fluid-venous fistula.

BACKGROUND: The frontotemporal brain sagging syndrome (FTBSS) is defined as an insidious/progressive decline in behavior and executive functions, hypersomnolence, and orthostatic headaches attributed to cerebrospinal fluid (CSF) hypovolemia. Here, a T6 CSF-venous fistula (e.g., between the subarachnoid CSF and a paraspinal vein) resulted in a CSF leak responsible for craniospinal hypovolemia. CASE DESCRIPTION: A 56-year-old male started with orthostatic headaches and fatigue after scuba diving. His symptoms included progressive, vertigo, tinnitus, nausea, lack of judgment, inappropriate behavior, memory dysfunction, apathy, tremor, orofacial dyskinesia, dysarthria, dysphagia, and hypersomnolence. The lumbar puncture revealed an opening pressure of 0 cm H2O. Magnetic resonance imaging (MRI) findings included brain sagging, bilateral temporal lobe herniation, and pachymeningeal enhancement. The computed tomography (CT) myelogram showed a thoracic diverticulum and a CSF-venous leak at the T6-T7 level. Surgery, which comprised a T6-T7 laminotomy, allowed for dissecting, clipping, and ligating the diverticulum/fistula. The patient improved postoperatively (e.g., cognitive, behavioral, and brainstem symptoms). The follow-up MRI's showed the reversion of the sagging index/uncal herniation. CONCLUSION: The FTBSS should be considered in the differential diagnosis of an early onset frontotemporal dementia. Establishing the diagnosis and localizing the site of a spinal CSF/venous leak warrant both MRI and myelogram CT studies, to pinpoint the CSF leak site for proper surgical clipping/ligation of these thoracic diverticulum/CSF-venous leaks.