Olivopontocerebellar atrophy is a neurodegenerative syndrome that arises spontaneously or through familial inheritance. This disease manifests as a part of other disorders, namely multiple system atrophy (MSA) and spinocerebellar ataxia (SCA).
Presentation
Olivopontocerebellar atrophy (OPCA) is a progressive disease, the sporadic form of which is now known as multiple system atrophy with cerebellar features (MSA-C), a subtype of multiple system atrophy (MSA). Its etiology is unknown. The inherited form of OPCA does not follow a single inheritance pattern which is, although, frequently autosomal dominant. Patients who present with the inherited form may have evidence of the illness in their family history. OPCA usually occurs in the middle aged, but the inherited form may develop in younger individuals. It rarely transpires after the seventh decade of life [1].
OPCA results from atrophy of structures in the brainstem and the cerebellum, thus its symptomatology is based on the dysfunction of these areas. There are several systems affected by OPCA, and the severity of symptoms worsens as the disease progresses. Autonomic dysregulation, if present, includes postural hypotension and gastrointestinal upset [2]. Genitourinary complaints range from urinary symptoms such as retention or incontinence to sexual dysfunction [3]. Pain may be experienced by a minority of patients.
Neurological symptoms and signs include worsening ataxia (one of the earliest signs), dysarthria, uncoordinated limb movements, unstable gait, hyperactive reflexes, and additional pyramidal as well as extrapyramidal manifestations [4]. Signs of parkinsonism such as cogwheel rigidity, postural instability, and tremor may be observed as the disease progresses. In addition, cognitive impairment and neuropathy have been reported.
Ocular dysfunction has been described, in the form of nystagmus, abnormal saccadic eye movements, as well as eye pathologies such as retinopathy [1]. Patients may experience dysphagia and recurrent laryngeal nerve paralysis, which causes stridor and can be rapidly fatal [5]. They are also at risk of aspiration, malnutrition, and traumatic injury from falls.
Patients with OPCA are prone to a number of sleep disturbance disorders such as rapid eye movement (REM) sleep behavior disorder RBD [6]. Furthermore, they have an increased susceptibility to psychiatric conditions such as depression and dementia.
Entire Body System
- Falling
This may include: Tremor medicines, such as those for Parkinson disease Speech, occupational and physical therapy Ways to prevent choking Walking aids to help with balance and prevent falls MSA-C slowly gets worse, and there is no cure. [nlm.nih.gov]
Falling is the major danger early in the disease, and assistive mobile devices such as walkers and wheelchairs are often essential to prevent falling. As the disease progresses, swallowing difficulties present the greatest danger. [encyclopedia.com]
This may include: Tremor medicines, such as those for Parkinson disease Speech, occupational and physical therapy Ways to prevent choking Walking aids to help with balance and prevent falls Support Groups The following groups can provide more information [mountsinai.org]
They are also at risk of aspiration, malnutrition, and traumatic injury from falls. Patients with OPCA are prone to a number of sleep disturbance disorders such as rapid eye movement (REM) sleep behavior disorder RBD. [symptoma.com]
- Movement Disorder
Munhoz and Tetsuo Ashizawa, Inherited and Sporadic Ataxias, Hyperkinetic Movement Disorders, (279-295), (2012). [doi.org]
Because it was induced by activation of the facial muscles, this movement disorder represents a form of action myoclonus. [ncbi.nlm.nih.gov]
Movement disorders Butterworths, London, 7: 249–269, 1987. Escourolle R., Masson M.:Atrophies cérébelleuses. In: Encyclopédie Médico-Chirurgicale, Editions Techniques, vol 3o, 17066 A 10, 1967. [link.springer.com]
Neuropathology of movement disorders. In: Winn HR, ed. Youmans and Winn Neurological Surgery. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 104. Ma MJ. Biopsy pathology of neurodegenerative disorders in adults. In: Perry A, Brat DJ, eds. [mountsinai.org]
Parkinson disease and other movement disorders. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice. 7th ed. Philadelphia, PA: Elsevier; 2016:chap 96. Ma MJ. [nlm.nih.gov]
- Fatigue
Very soon after beginning treatment for Multiple System Atrophy(MSA), Albert's coughing and choking while trying to drink were relieved, as was his muscle stiffness and fatigue. [puhuahospital.com]
Some patients also have fatigue and/or trouble with sleep. Generally symptoms of OPCA begin in mid-adult life and progress slowly over the course of many years. You can read more about hereditary and sporadic OPCA/ataxia. [alyshia.com]
[…] v=zxPS0UVCKzg Fact Sheets In 2015, the Multiple System Atrophy Trust in the UK published 25 fact sheets on topics such as bowel management, continence, fatigue, Parkinson’s medications, monitoring blood pressure, saliva, driving, and useful equipment [brainsupportnetwork.org]
Therapeutic Exercise/Activities: According to a study by Wedge, et al., gait training, transfer training, balance activities, and conditioning are necessary in reaching the goal of minimizing fatigue and risk for falling (safe transfers, etc.) [4] Resistance [physio-pedia.com]
Some patients also have fatigue and/or trouble with sleep. Generally, symptoms of OPCA begin in mid-adult life and progress slowly over the course of many years. [rarediseases.org]
- Difficulty Walking
There may also be problems with balance, slurring of speech, and difficulty walking. Olivopontocerebellar atrophy can be passed down through families (inherited form), or it may affect people without a known family history (sporadic form). [diseaseinfosearch.org]
There may also be problems with balance, slurring of speech, and difficulty walking. [nlm.nih.gov]
Other symptoms may include the following: Constipation Diarrhea Difficulties breathing or swallowing Difficulty walking Double vison or other vision problems Erectile dysfunction in men Generalized weakness Heart beat irregularities Incoordination Rigidity [healthcommunities.com]
- Impaired Balance
The patient developed dysarthria, followed by impaired balance of gait, mild limb ataxia, and saccadic eye movement. [ncbi.nlm.nih.gov]
Respiratoric
- Pneumonia
He had to remain in the ICU for 21 days on a ventilator even though he was hemodynamically stable with no evidence of pneumonia. [ncbi.nlm.nih.gov]
Complications of MSA-C include: Choking Infection from inhaling food into the lungs ( aspiration pneumonia ) Injury from falls Nutrition problems due to difficulty swallowing Call your health care provider if you have any symptoms of MSA-C. [nlm.nih.gov]
Possible Complications Complications of MSA-C include: Choking Infection from inhaling food into the lungs ( aspiration pneumonia ) Injury from falls Nutrition problems due to difficulty swallowing When to Contact a Medical Professional Call your health [mountsinai.org]
- Stridor
Although Stridor is more commonly found in multisystem atrophy, it is rarely seen in OPCA. We, here report a case of third decade onset of ataxia presenting with stridor. [ncbi.nlm.nih.gov]
Patients may experience dysphagia and recurrent laryngeal nerve paralysis, which causes stridor and can be rapidly fatal. They are also at risk of aspiration, malnutrition, and traumatic injury from falls. [symptoma.com]
Stridor is present in over one third of patients and has been reported previously as a presenting symptom in MSA: however previously reported patients have always gone on to develop other neurological symptoms. [cambridge.org]
- Aspiration
They are also at risk of aspiration, malnutrition, and traumatic injury from falls. Patients with OPCA are prone to a number of sleep disturbance disorders such as rapid eye movement (REM) sleep behavior disorder RBD. [symptoma.com]
Complications of MSA-C include: Choking Infection from inhaling food into the lungs ( aspiration pneumonia ) Injury from falls Nutrition problems due to difficulty swallowing Call your health care provider if you have any symptoms of MSA-C. [nlm.nih.gov]
Possible Complications Complications of MSA-C include: Choking Infection from inhaling food into the lungs ( aspiration pneumonia ) Injury from falls Nutrition problems due to difficulty swallowing When to Contact a Medical Professional Call your health [mountsinai.org]
- Abnormal Breathing
breathing at night or a harsh breathing sound (stridor) Sexual dysfunction Inability to achieve or maintain an erection (impotence) Loss of libido Cardiovascular problems Color changes in hands and feet caused by pooling of blood Psychiatric problems [mayoclinic.org]
As the neuron degeneration continues, symptoms are grouped into three categories: Autonomic malfunctions – drops in blood pressure, disturbance to sleep patterns due to abnormal breathing, abnormal sweating, decreased salivation and oil secretion causing [disability-benefits-help.org]
Gastrointestinal
- Choking
This may include: Tremor medicines, such as those for Parkinson disease Speech, occupational and physical therapy Ways to prevent choking Walking aids to help with balance and prevent falls MSA-C slowly gets worse, and there is no cure. [nlm.nih.gov]
This may include: Tremor medicines, such as those for Parkinson disease Speech, occupational and physical therapy Ways to prevent choking Walking aids to help with balance and prevent falls Support Groups The following groups can provide more information [mountsinai.org]
Upon diagnosis, the treatment options are symptomatic, as there is no cure for Hereditary Olivopontocerebellar Atrophy Additionally, treatment is used to help prevent complications, such as choking, infection of the lungs from inhaling food, and physical [dovemed.com]
Very soon after beginning treatment for Multiple System Atrophy(MSA), Albert's coughing and choking while trying to drink were relieved, as was his muscle stiffness and fatigue. [puhuahospital.com]
- Muscle Rigidity
A Japanese woman without a remarkable family history showed hand tremor at the age of 35 years, followed by bradykinesia, muscle rigidity, orthostatic hypotension, neurogenic bladder and pyramidal signs. No obvious cerebellar symptoms were found. [ncbi.nlm.nih.gov]
Additional clinical features may include MUSCLE RIGIDITY; NYSTAGMUS; RETINAL DEGENERATION; MUSCLE SPASTICITY; DEMENTIA; URINARY INCONTINENCE; and OPHTHALMOPLEGIA. [ucl.ac.uk]
Additional clinical features may include MUSCLE RIGIDITY; NYSTAGMUS, PATHOLOGIC; RETINAL DEGENERATION; MUSCLE SPASTICITY; DEMENTIA; URINARY INCONTINENCE; and OPHTHALMOPLEGIA. [profiles.umassmed.edu]
Medication may be given to: Relieve muscle rigidity Stabilize mood Manage orthostatic hypotension Relieve other symptoms such as constipation, urinary control problems, or erectile dysfunction Physical therapy—to help keep muscles strong and maintain [womenscenteroftexas.com]
- Diarrhea
Other symptoms may include the following: Constipation Diarrhea Difficulties breathing or swallowing Difficulty walking Double vison or other vision problems Erectile dysfunction in men Generalized weakness Heart beat irregularities Incoordination Rigidity [healthcommunities.com]
Eyes
- Abnormal Eye Movement
The clinical spectrum of olivopontocerebellar atrophy (OPCA) usually consists of pancerebellar signs with pyramidal and abnormal eye movements. Although Stridor is more commonly found in multisystem atrophy, it is rarely seen in OPCA. [ncbi.nlm.nih.gov]
Other symptoms may include: Abnormal eye movements Abnormal movements Bowel or bladder problems Difficulty swallowing Cold hands and feet Lightheadedness when standing Headache while standing that is relieved by lying down Muscle stiffness or rigidity [nlm.nih.gov]
Other symptoms may include problems with balance; speech or swallowing problems; difficulty walking; abnormal eye movements; muscle spasms; and neuropathy. [rarediseases.info.nih.gov]
Musculoskeletal
- Muscle Spasm
Other symptoms may include muscle spasms or weakness and stiffness of the muscles; numbness or tingling of the hands or feet; tremor (shaking) of the hand or arm; reduction or slowness of movements; loss of thinking and/or memory skills; difficulty controlling [alyshia.com]
Some of the more common symptoms of OPA may also include: tremor (shaking in the hands) bradykinesia (a slowness in the start of motion) slurred speech balance problems (such as weaving side to side when you walk) muscle spasms muscle stiffness and rigidity [healthline.com]
Other symptoms may include problems with balance; speech or swallowing problems; difficulty walking; abnormal eye movements; muscle spasms; and neuropathy. [rarediseases.info.nih.gov]
spasms Neuropathy (nerve damage) Tremors (shaking of the hand or arm) Cognitive decline The signs and symptoms can overlap with Parkinson’s disease, which can make the diagnosis challenging. [dovemed.com]
Other symptoms may include muscle spasms or weakness and stiffness of the muscles; numbness or tingling of the hands or feet; shaking (tremor) of the hand or arm; reduction or slowness of movements; loss of thinking and/or memory skills; difficulty controlling [rarediseases.org]
- Muscle Cramp
Some people may also have stiff and tense muscles. This can make it even more difficult to move around and cause painful muscle cramps (dystonia). [nhs.uk]
Urogenital
- Incontinence
Genitourinary complaints range from urinary symptoms such as retention or incontinence to sexual dysfunction. Pain may be experienced by a minority of patients. [symptoma.com]
Additional clinical features may include MUSCLE RIGIDITY; NYSTAGMUS; RETINAL DEGENERATION; MUSCLE SPASTICITY; DEMENTIA; URINARY INCONTINENCE; and OPHTHALMOPLEGIA. [ucl.ac.uk]
Urinary incontinence can be treated with medication, botox injections, catheters, or adult briefs. Therapy is worth trying: physical therapy, occupational therapy, and speech therapy. [brainsupportnetwork.org]
Additional clinical features may include MUSCLE RIGIDITY; NYSTAGMUS, PATHOLOGIC; RETINAL DEGENERATION; MUSCLE SPASTICITY; DEMENTIA; URINARY INCONTINENCE; and OPHTHALMOPLEGIA. [profiles.umassmed.edu]
Urogenital dysfunction resulting in urinary incontinence or erectile dysfunction is also common. MSA-P If features of Parkinsonism are present, symptoms may include slow movements, or bradykinesia, postural instability, and tremors. [news-medical.net]
- Urinary Incontinence
Additional clinical features may include MUSCLE RIGIDITY; NYSTAGMUS; RETINAL DEGENERATION; MUSCLE SPASTICITY; DEMENTIA; URINARY INCONTINENCE; and OPHTHALMOPLEGIA. [ucl.ac.uk]
Additional clinical features may include MUSCLE RIGIDITY; NYSTAGMUS, PATHOLOGIC; RETINAL DEGENERATION; MUSCLE SPASTICITY; DEMENTIA; URINARY INCONTINENCE; and OPHTHALMOPLEGIA. [profiles.umassmed.edu]
Other common symptoms can include severe orthostatic hypotension (blood pressure falls within three minutes of standing), urinary incontinence or urinary retention, erectile dysfunction in men, and REM sleep behavior disorder (RBD). [brainsupportnetwork.org]
Autonomic dysfunction (bladder dysfunction including early urinary incontinence, orthostatic hypotension, constipation, Raynaud syndrome) occurs early and is mandatory for the diagnosis of MSA-c. [orpha.net]
- Sexual Dysfunction
Genitourinary complaints range from urinary symptoms such as retention or incontinence to sexual dysfunction. Pain may be experienced by a minority of patients. [symptoma.com]
[…] disorders Agitated sleep due to "acting out" dreams Abnormal breathing at night or a harsh breathing sound (stridor) Sexual dysfunction Inability to achieve or maintain an erection (impotence) Loss of libido Cardiovascular problems Color changes in hands [mayoclinic.org]
dysfunction irregular heartbeats trouble with emotional regulation. [news-medical.net]
Sexual dysfunction, including erectile dysfunction in people who have a penis. Rapid eye movement (REM) sleep behavior disorder, similar to sleep problems in Parkinson’s disease. Decreased sweating (anhidrosis). Vision problems. Dry mouth. [my.clevelandclinic.org]
Neurologic
- Cerebellar Ataxia
Middle-aged patients who initially present with a progressive cerebellar ataxia, in the absence of a known familial pattern are often referred to under the descriptive diagnosis of 'idiopathic' late onset cerebellar ataxia. [ncbi.nlm.nih.gov]
Shoji Tsuji, Idiopathic Late Onset Cerebellar Ataxia (ILOCA), and Cerebellar plus Syndrome, Handbook of the Cerebellum and Cerebellar Disorders, 10.1007/978-94-007-1333-8_98, (2143-2150), (2013). [doi.org]
- Tremor
Stiffness, spasms, sleep disorders, depression, and tremor may be improved with medication. [ninds.nih.gov]
They occur in the young to middle-aged and are characterized by ataxia, dysarthria, and tremors similar to those of parkinsonism. progressive neuromuscular atrophy hereditary muscular atrophy beginning in the muscles supplied by the fibular (peroneal) [medical-dictionary.thefreedictionary.com]
For example medicines are prescribed for controlling tremors. Speech therapy helps the patient to improve his speech. [tandurust.com]
These were characterized by the co-existence of rhythmic skeletal myoclonus and parkinsonian tremor. [ncbi.nlm.nih.gov]
- Dysarthria
The patient developed dysarthria, followed by impaired balance of gait, mild limb ataxia, and saccadic eye movement. [ncbi.nlm.nih.gov]
They occur in the young to middle-aged and are characterized by ataxia, dysarthria, and tremors similar to those of parkinsonism. progressive neuromuscular atrophy hereditary muscular atrophy beginning in the muscles supplied by the fibular (peroneal) [medical-dictionary.thefreedictionary.com]
[…] ol·i·vo·pon·to·cer·e·bel·lar atrophy | \ -ˌpän-tō-ˌser-ə-ˈbel-ər- \ Medical Definition of ol i vo pon to cer e bel lar atrophy : an inherited disease especially of mid to late life that is characterized by ataxia, hypotonia, dysarthria, and degeneration [merriam-webster.com]
- Nystagmus
There was no pathologic nystagmus or saccadic dysmetria. Magnetic resonance imaging showed cerebellar and lower brainstem atrophy virtually diagnostic of olivopontocerebellar atrophy. [ncbi.nlm.nih.gov]
Additional features of MSA-c include dysphonia, dysphagia and other cerebellar features including limb ataxia and occulomotor dysfunction (sustained gaze-evoked nystagmus, positional down-beat nystagmus). [orpha.net]
Ocular dysfunction has been described, in the form of nystagmus, abnormal saccadic eye movements, as well as eye pathologies such as retinopathy. [symptoma.com]
- Clumsiness
Right limb clumsiness suggested corticospinal tract involvement. Gait was slightly wide based, but no other cerebellar or brainstem signs were present. [ncbi.nlm.nih.gov]
People who have ataxia may believe they are simply being clumsy. However, their clumsiness is actually a warning sign of their OPA. [healthline.com]
The main symptom is clumsiness (ataxia) that slowly gets worse. There may also be problems with balance, slurring of speech, and difficulty walking. [diseaseinfosearch.org]
The main symptom is clumsiness ( ataxia ) that slowly gets worse. There may also be problems with balance, slurring of speech, and difficulty walking. [nlm.nih.gov]
People in the beginning often misinterpret ataxia as clumsiness but in fact it is an indicating symptom of olivopontocerebellar atrophy. Patient finds difficult to keep balance of his body while walking. [tandurust.com]
Workup
Diagnosis of olivopontocerebellar atrophy (OPCA) entails:
- History: A family history of OPCA should be inquired as well as a history of symptoms experienced by the patient.
- Physical examination: This should include a thorough neurological exam.
- Genetic testing: The aid in the distinction between sporadic and hereditary OPCA.
- Imaging: This mostly consists of magnetic resonance imaging (MRI) scans, which may show signs of brain atrophy. A common sign is the "hot cross bun sign", which is present in over 80% of those with sporadic OPCA [7]. T2-weighted MRI, diffusion-weighted imaging (DWI), and diffusion tensor imaging (DTI) are the MRI techniques utilized [1].
- Further testing: This includes tests done to rule out other possible etiologies of the presenting symptoms.
Other Pathologies
- Gliosis
The nucleus basalis of Meynert had numerous NFTs with fibrillary gliosis and neuronal cell loss. The basis pontis was markedly atrophied and the pontine nucleus had severe neuronal depopulation and gliosis. [ncbi.nlm.nih.gov]
Treatment
Treatment There is no specific treatment for OPCA. Physicians may try different medications to treat the ataxia, tremor, and rigidity that are associated with the disorder. Other treatments are directed at specific symptoms. [ninds.nih.gov]
Is there any treatment? There is no specific treatment for OPCA. Physicians may try different medications to treat the ataxia, tremor, and rigidity that are associated with the disorder. Other treatments are directed at specific symptoms. [web.archive.org]
CONCLUSIONS: Buspirone treatment showed feasible efficacies for OPCA, while the combined treatment of estrogen and buspirone failed to improve, suggesting estrogen may not have further benefit in cerebellar dysfunction. [ncbi.nlm.nih.gov]
Treatments, therapies and strategies are available to help people with PSP and their families and carers to make the most of living with the condition. [parkinsonsvic.org.au]
Prognosis
Prognosis There is no cure for OPCA. The disorder is slowly progressive with death usually occurring approximately 20 years after onset. x Prognosis There is no cure for OPCA. [ninds.nih.gov]
Our review suggests that the label "OPCA" is useful to designate a clinicopathological syndrome that has a variety of etiologies carrying a poor prognosis, particularly if associated with autonomic failure as occurs in MSA. [ncbi.nlm.nih.gov]
Treatment can include medications for specific symptoms, therapy to help with speech and balance, and use of walking aids The prognosis for Hereditary Olivopontocerebellar Atrophy is generally poor as the central nervous system deterioration leads to [dovemed.com]
Etiology
Our review suggests that the label "OPCA" is useful to designate a clinicopathological syndrome that has a variety of etiologies carrying a poor prognosis, particularly if associated with autonomic failure as occurs in MSA. [ncbi.nlm.nih.gov]
Further testing: This includes tests done to rule out other possible etiologies of the presenting symptoms. [symptoma.com]
Etiology The exact etiology of MSC-c is unknown while the presence of cytoplasmic aggregates of α-synuclein, primarily in the oligodendroglia, in combination with predominant neurodegeneration of the olivopontocerebellar structures are pathological hallmark [orpha.net]
Abstract Spinocerebellar degeneration or olivopontocerebellar degeneration denotes a group of disorders of various etiologies manifesting as degenerative changes of various part of the central nervous system. [unboundmedicine.com]
2016 2017 2018 2019 2020 2021 2022 2023 - Revised Code Billable/Specific Code Applicable To Mild cognitive disorder NOS Mild neurocognitive disorder of uncertain or unknown etiology Type 1 Excludes age related cognitive decline (R41.81) altered mental [icd10data.com]
Epidemiology
For a discussion of epidemiology and pathology, please refer to: multiple systemic atrophy (MSA). Clinical presentation Olivopontocerebellar degeneration presents predominantly with cerebellar and brainstem symptoms and signs. [radiopaedia.org]
Patient Epidemiology Analysis Olivopontocerebellar Atrophy (OPCA) market also provides you with detailed market analysis for patient analysis, prognosis and cures. [databridgemarketresearch.com]
Summary Epidemiology MSA-c is observed predominantly in patients from Asia. [orpha.net]
Epidemiology Frequency The prevalence of OPCA is 3–5 cases per 100,000 individuals; this may represent approximately 5–6% of patients diagnosed with atypical Parkinson disease. [emedicine.com]
Pathophysiology
The pathophysiology of blepharospasm appears to involve an increased excitability of the interneurons of the blink and corneal reflexes. [ncbi.nlm.nih.gov]
Prevention
The aim is to treat the symptoms and prevent complications. [nlm.nih.gov]
Treatments and therapies are available to help manage symptoms of CBS, however there is no cure or ways to prevent it from occurring or slow its progression. [parkinsonsvic.org.au]
The NINDS supports and conducts a broad range of basic and clinical research on cerebellar degeneration, including work aimed at finding the cause(s) of OPCA and ways to treat, cure, and, ultimately, prevent the disease. [web.archive.org]
References
- Gilman S, Wenning GK, Low PA, et al. Second consensus statement on the diagnosis of multiple system atrophy. Neurology. 2008;71(9):670–676.
- Wenning GK, Ben-Shlomo Y, Magalhães M, Daniel SE, Quinn NP. Clinical features and natural history of multiple system atrophy. An analysis of 100 cases. Brain. 1994;117(Pt 4):835–845.
- Kirchhof K, Apostolidis AN, Mathias CJ, Fowler CJ. Erectile and urinary dysfunction may be the presenting features in patients with multiple system atrophy: a retrospective study. Int J Impot Res. 2003;15(4):293–298.
- Iodice V, Lipp A, Ahlskog JE, et al. Autopsy confirmed multiple system atrophy cases: Mayo experience and role of autonomic function tests. J Neurol Neurosurg Psychiatry. 2012;83(4):453–459.
- Isozaki E, Naito A, Horiguchi S, Kawamura R, Hayashida T, Tanabe H. Early diagnosis and stage classification of vocal cord abductor paralysis in patients with multiple system atrophy. J Neurol Neurosurg Psychiatry. 1996;60(4):399–402.
- Shimohata T, Nakayama H, Tomita M, Ozawa T, Nishizawa M. Daytime sleepiness in Japanese patients with multiple system atrophy: prevalence and determinants. BMC Neurol. 2012;12:130.
- Watanabe H, Saito Y, Terao S, et al. Progression and prognosis in multiple system atrophy: an analysis of 230 Japanese patients. Brain. 2002;125(Pt 5):1070–1083.