Hemiparkinsonism associated with a mesencephalic tumor

Paraneoplastic Neurological Syndromes of the Central Nervous System: Pathophysiology, Diagnosis, and Treatment

Paraneoplastic neurological syndromes (PNS) include any symptomatic and non-metastatic neurological manifestations associated with a neoplasm. PNS associated with antibodies against intracellular antigens, known as "high-risk" antibodies, show frequent association with underlying cancer. PNS associated with antibodies against neural surface antigens, known as "intermediate- or low-risk" antibodies, are less frequently associated with cancer. In this narrative review, we will focus on PNS of the central nervous system (CNS). Clinicians should have a high index of suspicion with acute/subacute encephalopathies to achieve a prompt diagnosis and treatment. PNS of the CNS exhibit a range of overlapping "high-risk" clinical syndromes, including but not limited to latent and overt rapidly progressive cerebellar syndrome, opsoclonus-myoclonus-ataxia syndrome, paraneoplastic (and limbic) encephalitis/encephalomyelitis, and stiff-person spectrum disorders. Some of these phenotypes may also arise from recent anti-cancer treatments, namely immune-checkpoint inhibitors and CAR T-cell therapies, as a consequence of boosting of the immune system against cancer cells. Here, we highlight the clinical features of PNS of the CNS, their associated tumors and antibodies, and the diagnostic and therapeutic strategies. The potential and the advance of this review consists on a broad description on how the field of PNS of the CNS is constantly expanding with newly discovered antibodies and syndromes. Standardized diagnostic criteria and disease biomarkers are fundamental to quickly recognize PNS to allow prompt treatment initiation, thus improving the long-term outcome of these conditions.

Movement Disorders in Oncology: From Clinical Features to Biomarkers

Background: the study of movement disorders associated with oncological diseases and anticancer treatments highlights the wide range of differential diagnoses that need to be considered. In this context, the role of immune-mediated conditions is increasingly recognized and relevant, as they represent treatable disorders. Methods: we reappraise the phenomenology, pathophysiology, diagnostic testing, and treatment of movement disorders observed in the context of brain tumors, paraneoplastic conditions, and cancer immunotherapy, such as immune-checkpoint inhibitors (ICIs). Results: movement disorders secondary to brain tumors are rare and may manifest with both hyper-/hypokinetic conditions. Paraneoplastic movement disorders are caused by antineuronal antibodies targeting intracellular or neuronal surface antigens, with variable prognosis and response to treatment. ICIs promote antitumor response by the inhibition of the immune checkpoints. They are effective treatments for several malignancies, but they may cause movement disorders through an unchecked immune response. Conclusions: movement disorders due to focal neoplastic brain lesions are rare but should not be missed. Paraneoplastic movement disorders are even rarer, and their clinical-laboratory findings require focused expertise. In addition to their desired effects in cancer treatment, ICIs can induce specific neurological adverse events, sometimes manifesting with movement disorders, which often require a case-by-case, multidisciplinary, approach.

Localizing parkinsonism based on focal brain lesions

Bradykinesia, rigidity, and tremor frequently co-occur, a clinical syndrome known as parkinsonism. Because this syndrome is commonly seen in Parkinson's disease, symptoms are often attributed to cell loss in the substantia nigra. However, parkinsonism occurs in several other neurological disorders and often fails to correlate with nigrostriatal pathology, raising the question of which brain region(s) cause this syndrome. Here, we studied cases of new-onset parkinsonism following focal brain lesions. We identified 29 cases, only 31% of which hit the substantia nigra. Lesions were located in a variety of different cortical and subcortical locations. To determine whether these heterogeneous lesion locations were part of a common brain network, we leveraged the human brain connectome and a recently validated technique termed lesion network mapping. Lesion locations causing parkinsonism were functionally connected to a common network of regions including the midbrain, basal ganglia, cingulate cortex, and cerebellum. The most sensitive and specific connectivity was to the claustrum. This lesion connectivity pattern matched atrophy patterns seen in Parkinson's disease, progressive supranuclear palsy, and multiple system atrophy, suggesting a shared neuroanatomical substrate for parkinsonism. Lesion connectivity also predicted medication response and matched the pattern of effective deep brain stimulation, suggesting relevance as a treatment target. Our results, based on causal brain lesions, lend insight into the localization of parkinsonism, one of the most common syndromes in neurology. Because many patients with parkinsonism fail to respond to dopaminergic medication, these results may aid the development of alternative treatments.10.1093/brain/awy161_video1awy161media15815555971001.

Adult brainstem gliomas

Brainstem gliomas in adults are a rare and heterogeneous group of brain tumors that vary with regard to underlying pathology, radiographic appearance, clinical course and prognosis. Diffuse intrinsic pontine gliomas represent the most common subtype. Although still considered aggressive and most often lethal, these brain tumors are associated with a more insidious clinical course and more favorable prognosis compared to the highly aggressive form in children. Treatment options for patients with brainstem gliomas still are limited and insufficiently studied. A better understanding of the pathobiology of these tumors will be crucial for the development of more specific and effective therapies. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2799-2809. © 2016 American Cancer Society.

Adult brainstem gliomas

Brainstem gliomas are uncommon in adults and account for only 1%-2% of intracranial gliomas. They represent a heterogeneous group of tumors that differ from those found in their pediatric counterparts. In adults, a low-grade phenotype predominates, which is a feature that likely explains their better prognosis compared to that in children. Because biopsies are rarely performed, classifications based on the radiological aspect of magnetic resonance imaging results have been proposed to establish treatment strategies and to determine outcomes: (a) diffuse intrinsic low-grade, (b) enhancing malignant glioma, (c) focal tectal gliomas, and (d) exophytic gliomas. Despite significant advances in neuroradiology techniques, a purely radiological classification remains imperfect in the absence of a histological diagnosis. Whereas a biopsy may often be reasonably avoided in the diffuse nonenhancing forms, obtaining histological proof seems necessary in many contrast-enhanced brainstem lesions because of the wide variety of differential diagnoses in adults. Conventional radiotherapy is the standard treatment for diffuse intrinsic low-grade brainstem gliomas in adults (the median survival is 5 years). In malignant brainstem gliomas, radiotherapy is the standard treatment. However, the possible benefit of combined radiotherapy and chemotherapy (temozolomide or other agents) has not been thoroughly evaluated in adults. The role of anti-angiogenic therapies in brainstem gliomas remains to be defined. A better understanding of the biology of these tumors is of primary importance for identifying homogeneous subgroups and for improving therapy options and outcomes.

Postanoxic akinesia with bilateral pallidal lesions: a PET study

A 70-year-old woman developed marked akinesia after an anoxic event related to bronchiectasia. Magnetic resonance imaging studies revealed lesions in the bilateral globus pallidus and, to a lesser extent, in the putamen. Positron emission tomography studies with (18)F-6-fluoro-L-dopa and (11)C-N-methylspiperone showed a decreased pre- and post-synaptic uptake in the striatum. Consistent with previous reports, the present case demonstrated the basal ganglia, particularly the globus pallidus, to be selectively susceptible to anoxic insults. Furthermore, a PET study indicated a disrupted presynaptic integrity of the dopaminergic terminals and decreased dopamine D(2) receptor binding, which together appear to underlie the pathophysiology of post-anoxic akinesia, at least in the present case.

Clinicoradiological changes of brain NK/T cell lymphoma manifesting pure akinesia: a case report

Background

Pure akinesia (PA) is a distinct form of parkinsonism characterized by freezing phenomena. Little is known about brain tumor-associated PA. We highlight the clinicoradiological changes in a patient with PA and central nervous system (CNS) metastases of natural killer/T-cell lymphoma (NKTL).

Case presentation

A 68-year-old man with stage IVB extranodal NKTL developed a gait disturbance. Neurological examination of his gait revealed freezing, start hesitation, short step, forward flexion posture, festination and postural instability. Mild facial hypomimia and micrographia were observed. There was no rigidity or tremor in any of the four extremities. Brain magnetic resonance imaging (MRI) displayed T2-hyperintense lesions in the dorsal brainstem, cerebellum and periventricular white matter. Diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) revealed hyperintensity in these regions. Cerebrospinal fluid cytology revealed CD56-positive cells on immunohistochemical staining. The patient's neurological deficits did not respond to L-dopa treatment and intrathecal administration of methotrexate (MTX). Two weeks later, he displayed confusion and generalized convulsions. T2-hyperintense lesions spread to the basal ganglia and the infratentorial regions. Gadolinium enhancement was observed in the cerebellum and frontal subcortex. DWI and the ADC revealed diffusion-restricted lesions in the middle cerebellar peduncles, left internal capsules and cerebral white matter. MTX pulse therapy and intrathecal administration of cytosine arabinoside and MTX were performed. Two months later, his ambulatory state was normalized. Brain MRI also revealed marked alleviation of the infratentorial and supratentorial lesions.

Conclusions

The clinicoradiological profile of our patient suggested that dorsal ponto-mesencephalic lesions could contribute to the pathogenesis of PA. Physicians should pay more attention to striking CNS seeding of metastatic NKTL. MTX pulse therapy had an excellent effect in improving serious symptoms and brain lesions in our patient.

Extranigral extension of structural midbrain lesions overshadows parkinsonism

We report on a clinicoanatomical analysis of five patients with structural midbrain lesions who shared severe nigrostriatal dopaminergic denervation but presented different involuntary movements. The main clinical phenotype was parkinsonism in only one case; it was choreoballism in three cases and tremor and dystonia in one case. Structural midbrain lesions are likely to involve structures additional to nigral dopaminergic neurons. The extent of extranigral involvement may determine the diverse clinical manifestations associated with the structural midbrain lesions.

Cerebral infratentorial large B-cell lymphoma presenting as Parkinsonism

Though rare, primary intracranial tumors can present with Parkinsonian symptoms, and diagnosis can be delayed unless there is a high index of suspicion. We herein present an 81-year-old man who was seen in our neurology clinic due to acute onset of unsteady gait and altered consciousness. Parkinsonism was initially diagnosed because of the typical manifestations. Levodopa was prescribed; however, there was a limited effect on his symptoms. Upon detail history and neurological examination, left sided hemiparesis was disclosed. Cerebral imaging studies revealed a solid mass over the right infratentorial para-midbrain area leading to reactive obstructive hydrocephalus. Work-up including chest and abdominal CT scanning, upper and lower GI endoscopy, and tumor marker studies failed to uncover any abnormalities. A neurosurgeon was consulted and a shunt procedure and biopsy of the infratentorial mass were performed. Histopathological examination of the biopsy tissue revealed tumor diffusely intermixed with large cells consistent with large B-cell lymphoma. The patient and his family declined further treatment. Though rare, cerebral tumors can present with Parkinsonian features and represent a diagnostic challenge. Clinicians should be aware of the possibility of cerebral neoplasms causing Parkinsonism, and include them in the differential diagnosis, especially for patients presenting with atypical Parkinsonian features, or those not responsive to initial therapy.

Hemiparkinsonism due to a pontomesencephalic cavernoma: improvement after resection. Case report

Cavernous angiomas of the upper brainstem causing hemiparkinsonism are very rare. Due to their difficult-to-reach localization, brainstem cavernomas, in particular those in anterior locations, continue to present a therapeutic challenge. The authors report on a 16-year-old boy with a pontomesencephalic cavernoma who developed hemiparkinsonism and hemiparesis after hemorrhage. After complete surgical removal of the pontomesencephalic cavernoma via a pterional transsylvian approach, his symptoms resolved. Although pontomesencephalic cavernomas occupying the ventral portion of the brainstem are regarded as problematic for resection, the pterional transsylvian approach provides an excellent route for removal of cavernomas that are in contact with the ventral surface of the midbrain in the interpeduncular cistern. Surgical removal of this type of lesion is recommended because resolution of clinical symptoms, including hemiparkinsonism, can be achieved.

Hemiparkinsonism secondary to an infiltrative astrocytoma

BACKGROUND

Brain tumors are uncommon etiologies of parkinsonism. The clinical manifestations of tumoral parkinsonism may sometimes resemble those of idiopathic origin. Increased awareness of this rare entity is important for an earlier prompt diagnosis and treatment.

REVIEW SUMMARY

A previously healthy, 60-year-old man developed slowly progressive right-sided resting tremor and bradykinesia over 8 months. Although idiopathic Parkinson disease was the initial diagnosis, the parkinsonian symptoms were not responsive to medical treatment with levodopa and a dopamine agonist. Brain computed tomography failed to reveal an intracranial lesion. Brain magnetic resonance imaging demonstrated an infiltrative, slightly enhancing mass in the left mesial temporal lobe extending to the left basal ganglion and insula. Histopathologic findings confirmed the diagnosis of high-grade astrocytoma. The parkinsonian symptoms subsided after tumor removal; however, ipsilateral hemiparesis developed postoperatively.

CONCLUSIONS

Neuroimaging is recommended for investigation of atypical parkinsonism. We suggest that brain magnetic resonance imaging is preferred for patients with drug-resistant parkinsonism or concurrent signs apart from extrapyramidal symptoms, because some mass lesions are not observed by computed tomography scan.

Impact of surgical treatment on tremor due to posterior fossa tumors

Object

The object of this study was to investigate the impact of surgical treatment on tremor caused by posterior fossa tumors.

Methods

The authors performed a retrospective evaluation of 6 cases involving patients with tremors due to posterior fossa tumors. Patients who had been treated with neuroleptic medication or had a family history of movement disorders were excluded. All patients had postural or kinetic tremors. Tremor was mainly unilateral. The study group included 5 women and 1 man. Mean age at surgery was 59 years. Five patients underwent total or subtotal tumor resection, and 1 patient underwent stereotactic biopsy only. The histological diagnosis was epidermoid tumor in 2 patients, metastasis in 2 others, and vestibular schwannoma and low-grade glioma in 1 each.

Results

Two patients had no improvement of tremor, postoperatively. In both of these patients the tumor (low-grade glioma in 1, metastasis in the other) involved the dentate nucleus directly. In the other patients, a compressive effect on the dentate nucleus or the dentatothalamic pathways was present without invasion of the cerebellar structures, and immediate or gradual amelioration of the tremor was observed postoperatively.

Conclusions

The prognosis of tremor due to posterior fossa tumors appears to depend mainly on the involvement of tremor-generating structures. The prognosis appears to be favorable in those patients with compression of these substrates, whereas primary invasion by tumor has a poor prognosis. Caution must be used in generalizing the findings of this study because of the small number of cases in the series.

Relapsing hemiparkinsonism due to recurrent meningioma

We describe a case with left hemiparkinsonism due to a parasagittal meningioma with surrounding edema compressing the right basal ganglia. The patient was successfully operated and his symptoms resolved completely. However 7 years later his hemiparkinsonism reappeared due to a relapse of the right parasagittal meningioma. This rare case points to the significance of neuroimaging in the evaluation of parkinsonism.

Mesencephalic cryptococcal abscesses presenting with parkinsonism as an initial manifestation of AIDS

Parkinsonism has been associated with HIV/AIDS and cerebral cryptococcal disease, but to date there has been no report of histological cryptococcal lesions in the substantia nigra (SN) in a patient with parkinsonism. We report on a case of a 63-year-old man who presented with tremor, gait disturbance, and mask-like facies, and showed cryptococcal meningoencephalitis with cryptococcal abscesses in the SN at autopsy, without Lewy bodies or significant degeneration of the SN neurons. Parkinsonism also represented the first manifestation of AIDS in this previously undiagnosed patient. This case highlights the importance of considering infectious etiologies in patients presenting with parkinsonism, and underscores the need for autopsy in evaluation of patients with new or unexplained movement disorders. Movement disorders in association with AIDS and mesencephalic mass lesions are discussed.