Postoperative pediatric cerebellar mutism syndrome and. Mri shows an ill defined, t2 low signal intensity foci in the lower pons suggesting hemosiderin and ferritin deposits with relatively well defined t2 hyperintensity and enlargement of the left anterior medulla in the inferior olivary nucleus region with no restricted diffusion, suggesting possible hypertrophic olivary degeneration hod. Hypertrophic olivary degeneration is a rare form of neuronal degeneration that results from disruption of the afferent fibres to the inferior olive within the dentatorubroolivary tract, otherwise known as the triangle of guillainmollaret. Hypertrophic olivary degeneration hod is a disease that can be a complication of brainstem or cerebellar hemorrhage or surgery including radiosurgery. The aim of the study is to analyze diffusion tensor imaging dti characteristics of the guillain. The dentatothalamocortical dtc pathway is recognized as the anatomical substrate for postoperative pediatric cerebellar mutism popcms, a wellrecognized complication affecting up to 31% of children undergoing. Cavernous malformation of midbrain resulting in bilateral right more than left increase t2 signal and slight mass effect of the inferior olivary nuclei, suggesting the diagnosis of hypertrophic olivary degeneration. The clinical syndrome of hod occurs slowly over months and may be overlooked in progressive neurooncological diseases. We report two cases of hod in two different clinical scenarios. Imaging features of hypertrophic olivary degeneration. Typical magnetic resonance imaging findings include t2hyperintensity and enlargement of the inferior olivary nucleus evolving over time to. Bilateral hypertrophic olivary degeneration europe pmc. Hypertrophic olivary degeneration cerebrovascular disease.
Hypertrophic olivary degeneration with associated dentate nucleus lesion. Hypertrophic olivary degeneration hod is a rare neurological condition caused by degeneration in the brain stem, the structure that connects the brain to the spinal cord. Hypertrophic degeneration of the inferior olive is mainly observed in patients developing palatal tremor pt or oculopalatal tremor opt. Diffusion tensor imaging data were acquired on a 1. Hypertrophic olivary degeneration a report of two cases. Mri and neurological presentation of hypertrophic olivary.
We present new radiologic findings of hod in 2 cases of brainstem lymphoma. Hypertrophic olivary degeneration genetic and rare diseases nih. Postoperative pediatric cerebellar mutism syndrome and its. Dekeyzer hypertrophic olivary degeneration hod is a unique form of transneuronal degeneration caused by a. Unilateral hypertrophic olivary degeneration right due to left cerebellous hematoma due to lesion of the left dentate nuclei and dentorubral tract. Hypertrophic olivary degeneration may be a surrogate imaging indicator for damage to the contralateral proximal efferent cerebellar pathway. Hypertrophic olivary degeneration hod is a rare transsynaptic degeneration that usually appears at around 34 weeks. We used track density imaging, which provides unprecedented anatomic details based on probabilistic tractography streamlines, to demonstrate apparent changes in the integrity of the dentatorubroolivary pathway guillainmollaret triangle that were consistent with the diagnosis of hypertrophic olivary degeneration from the antecedent ms. Hypertrophic olivary degeneration is a unique type of transsynaptic neuronal degeneration caused by damage to the dentatorubral pathway or the triangle of guillain and mollaret. Mollaret triangle gmt in patients with hypertrophic olivary degeneration hod and to investigate their correlation with previously reported histopathology. Investigate the relative frequency of nonlesional versus lesional hypertrophic olivary degeneration hod and potential explanations for nonlesional hod. Dtistudio, diffeomap, and roieditor software available at.
A 71yearold man presented with a 2week history of nausea, vomiting, unsteady gait, and diplopia. The degeneration is unique in that it is associated. In the appropriate clinical setting, bilateral hypertrophic olivary degeneration may be a sensitive. Hypertrophic olivary degeneration hod is an uncommon pathological entity characterized by transsynaptic degeneration secondary to lesions in the dentorubro olivary tract or the guillainmollaret triangle discovered in 1931 by guillain and mollaret. Hypertrophic olivary degeneration is a transsynaptic form of degeneration, which is also a result of. This syndrome manifests as a synchronous tremor of the palate pt andor eyes opt that may also involve other muscles from the branchial arches.
Posterior fossa tumors are often located near these. Hypertrophic olivary degeneration genetic and rare. Not seen on ct scan due to artefacts caused by bony structures, the hypertrophic olivary degeneration hod is more recently detected in vivo by mri and is characterized by an hypersignal of the olive of the medulla oblongata on pdt2 images with a variable enlargement of the olive itself. Figure 1 ct and mri scan results in a case of hypertrophic olivary degeneration following resection of a cavernoma in the brain stem. We report a case of hypertrophic olivary degeneration hod detected by mri, in a 14yearold girl, months after surgical excision of a brainstem cavernous malformation. A 30yearold man underwent mri of the internal auditory meatus as a routine followup after excision of a large left vestibular schwannoma, 2. Hypertrophic olivary degeneration may be a surrogate imaging indicator for damage of the contralateral proximal efferent cerebellar pathway. Signs and symptoms include palatal tremors, lack of movement coordination ataxia, holmes tremor, vision problems, muscle weakness, and gait impairment, along with an mri. Hypertrophic olivary degeneration neuroradiology cases. Hypertrophic olivary degeneration hod is a dynamic process caused by. The syndrome of oculopalatal tremor is a known consequence of lesions in the dentate olivary pathway. Mr imaging showed enlargement of the right medullary olive and a vascular lesion in the right pontine tegmentum.
Unusual clinical manifestation associated with hypertrophic olivary. Characteristic hypertrophic changes are because of transsynaptic degeneration, because of. Hypertrophic olivary degeneration is a form of transsynaptic degeneration with hypertrophy rather than atrophy of the inferior olivary nucleus in response to neurologic insult to the dentatorubroolivary pathway. In this case, the previous hemorrhagic lesion in the right dentate nucleus caused the interruption. As in vivo diagnosis of this condition has only become possible with the advent of mri, the number of reported cases remains relatively small and they are almost exclusively in adults. Magnetic resonance imaging figure 1bd showed findings consistent with hypertrophic olivary degeneration, ipsilateral to the prior bleed that had involved the central tegmental tract. Hypertropic olivary degeneration secondary to dilated. This phenomenon occurs as a result of wallerian degeneration of the olivary nucleus secondary to a lesion in the triangle. Diffusion tensor imaging in hypertrophic olivary degeneration. To discuss the radiological features of hypertrophic olivary degeneration hod, with emphasis on underlying neuroanatomy. Unusual clinical manifestation associated with hypertrophic. Signs and symptoms include palatal tremors, lack of movement coordination ataxia, holmes tremor, vision problems, muscle weakness, and gait impairment, along with an mri showing enlargement.
Delayed occurrence of hypertrophic olivary degeneration after therapy of posterior. Mri findings in nonlesional hypertrophic olivary degeneration. This was accompanied by magnetic resonance imaging. Hypertrophic olivary degeneration hod is a rare transsynaptic degeneration that usually appears at around 34 weeks following an injury to the guillainmollaret triangle. In some case series, half of the patients with hod have developed it as a result of a brainstem cavernous angioma hemorrhage or surgery.
This phenotype of oculopalatal tremor is associated with unilateral or bilateral hypertrophic inferior olive io degeneration that is visible with conventional mri. A 59yearold male with untreated hypertension suffered a primary pontine hemorrhage, which caused horizontal eyemovement limitation. The left ich and enlargement of the right medullary olive suggesting hypertrophic olivary degeneration with disruption of dentatorubro olivary pathway figure 2 was thought to cause the presentation of pm, holmes or cerebellar tremor, and secondary parkinsonism. These connections have been shown to be tightly associated, as degeneration of either the cerebellum or the ion results in. Hypertrophic olivary degeneration in a child following midbrain. Hypertrophic olivary degeneration hod is caused by disruptive lesions affecting components of the guillainmollaret triangle gmt. Developed by renowned radiologists in each specialty, statdx provides comprehensive decision support you can rely on hypertrophic olivary degeneration. As patients can be asymptomatic, it can be an incidental imaging finding, and radiologists should be aware of its typical imaging characteristics. Testing asymptomatic children insurancetesting lab info free genetic testing program patient booklet. Hypertrophic olivary degenerationmri sumers radiology blog. Delayed occurrence of hypertrophic olivary degeneration. Progressive neurological deterioration with involuntary eye and palatal movements began months after hemorrhage.
Inferior olivary nucleus hypertrophy may lead to misdiagnosis of hypertrophic olivary degeneration as. Hypertrophic olivary degeneration after cerebellar or brain. Hypertrophic olivary degeneration radiology reference. Full text a case of hypertrophic olivary degeneration after resection. Hypertrophic olivary degeneration hod is a rare abnormality that is. To assess magnetic resonance mr imaging findings of hypertrophic olivary degeneration hod due to hemorrhage and correlate them with pathologic findings. We present conventional magnetic resonance and diffusion tensor imaging dti findings in a 6yearold girl with hod after surgery for a midbrain pilocytic astrocytoma. New radiologic findings of hypertrophic olivary degeneration in 2. It is caused by a lesion in the triangle of guillain and mollaret, resulting in hypertrophy of the inferior olivary nucl. Histologic and imaging changes t2 hyperintensity begin approximately 3 weeks after initial injury in most patients but can first appear on. Dincer a, ozyurt o, kaya d, kosak e, ozturk c, erzen c, pamir mj.
Abstract the aim of the study is to analyze diffusion tensor imaging dti characteristics of the guillainmollaret triangle gmt in patients with hypertrophic olivary degeneration hod and to investigate their correlation with previously reported histopathology. Magnetic resonance imaging of hypertrophic olivary. Diffusion tensor imaging in a child with hypertrophic. Signs and symptoms include palatal tremors, lack of movement coordination ataxia, holmes tremor, vision problems, muscle weakness, and gait impairment, along with an mri showing enlargement hypertrophy of the inferior. Mri images showed an incidental finding of left hypertrophic olivary degeneration figure 1 and figure 2. Hypertrophic olivary degeneration is a rare form of neuronal degeneration that results from disruption of the afferent fibres to the inferior olive within the dentatorubro olivary tract, otherwise known as the triangle of guillainmollaret. Jun 29, 2017 hypertrophic degeneration of the inferior olive is mainly observed in patients developing palatal tremor pt or oculopalatal tremor opt.
Hypertrophic degeneration of the inferior olive is a recognized pathological correlate of these lesions and. Ventromedial portions of both half of medulla show enlargement with t2 hyper intensity implies to bilateral hypertrophic olivary degeneration explained by involvement of central tegmental tract, cerebellar peduncle and dentate nucleus of cerebellum. A rare presentation of hypertrophic olivary degeneration. Hypertrophic olivary degeneration hod is a rare neurological condition caused by degeneration in the brain stem, the structure that connects. Mri also showed a slightly increased t2 signal intensity in the right. Oculopalatal tremor following sequential medullary infarcts. Temporal evolution of hypertrophic olivary degeneration hod. In this patient with a history of resected pilocytic astrocytoma of the midbrain and uvulopalatal tremor, a stable lesion is present in the right meduallary olive remote from the surgical site. Hod usually occurs uni and ipsilaterally to the lesion if the lesion is in the brainstem or contralaterally to the lesion if the lesion is in the cerebellum, as has been shown by mri. Diffusion tensor imaging in a case of pontine bleeding showing. Bilateral hypertrophic olivary degeneration in wilson disease. Oculopalatal tremor is a distinct ocular and palatal oscillation that is often found as a late consequence of a lesion within the dentato olivary pathway. Although the imaging features have been well described, the temporal course of hypertrophy and t2 signal increase in the inferior olivary nucleus ion has not. Imaging features were consistent with bilateral hypertrophic olivary degeneration.
The forgotten triangle of guillain and mollaret sir, hypertrophic olivary degeneration hod, a form of transsynaptic degeneration, results from a lesion of the dentorubro olivary pathway also called the anatomical triangle of guillain and mollaret. Hypertrophic olivary degeneration introduction hypertrophic olivary degeneration hod is usually caused by a lesion along the dentaterubroolivary pathway, also known as the anatomic triangle of guillainmollaret. Frontiers longitudinal quantification of eyemovement. New radiologic findings of hypertrophic olivary degeneration. Hypertrophic olivary degeneration after surgical resection of. The pathophysiological basis for hypertrophic olivary. Postoperative pediatric cerebellar mutism syndrome and its association with hypertrophic olivary degeneration background. Imaging features of hypertrophic olivary degeneration ruth van eetvelde, m. This is unique because the inferior olivary nucleus hypertrophies following degeneration unlike the typical atrophy seen in other structures. It is associated with hypertrophic inferior olivary degeneration that is characterized by enlarged and. Hypertrophic olivary degeneration hod is a rare condition caused by a unique pattern of transsynaptic degeneration, thought to be associated.
Hypertrophic olivary degeneration hod occurs in lesions involving the dentatorubro olivary system. Diffusion tensor imaging of guillainmollaret triangle in. Hypertrophic olivary degeneration is a unique type of transneural degeneration caused by a variety of primary lesions in the dentorubro olivary pathway or guillainmollaret triangle. Hypertrophic olivary degeneration hod is a rare neurological condition of transsynaptic degeneration caused by disruption of the dentatorubro olivary pathway. There is an area of abnormal t2 hyperintensity involving the right dentate nucleus with associated ring enhancing lesion a and b. Hypertrophic olivary degeneration hod hypertrophic olivary degeneration hodoften detected by increased t2 signal intensity on mrican occur after damage to the dentatorubro olivary pathway via cerebrovascular diseases such as stroke or hemorrhage. Hypertrophic olivary degeneration hod is usually caused by a lesion in the triangle of guillain and mollaret and presents clinically as palatal tremor. Delayed occurrence of hypertrophic olivary degeneration after. Our radiology report database was queried for hod in all head mri reports between 712002 and 7120 and identified 8 patients. Background hypertrophic olivary degeneration hod can be seen as high signal intensity with enlargement of the inferior olivary nucleus ion on t2weighted ma. Bilateral hypertrophic olivary nucleus degeneration on magnetic resonance imaging in children with leigh and leighlike syndrome the british journal of radiology, vol. Jan 27, 2017 hypertrophic olivary degeneration hod is a rare neurological condition caused by degeneration in the brain stem, the structure that connects the brain to the spinal cord. Magnetic resonance imaging of the brain revealed a gadoliniumenhanced lesion involving the superior vermis and the right middle cerebellar peduncle figure 1a and b.
Magnetic resonance imaging of the brain showed an area of increased signal on diffusionweighted images of the dorsal. Letters to editor hypertrophic olivary degeneration. Disrupting the guillainmollaret triangle leads to degeneration of the ion, 23. Bilateral inferior olivary nuclei are enlarged and hyperintense on t2 weighted imaging wifluid attenuation inversion recovery, hypointense on t1wi with effacement of pre and post olivary sulci and no enhancement on contrast administration consistent with bilateral hypertrophic olivary degeneration figure 2. Comparison of postoperative subjects with and without posterior fossa syndrome. Guillainmollarettriangle and the typical imaging findings of hypertrophic olivary degeneration. Frontiers hypertrophic olivary degeneration and palatal. Typically t 2 hyperintensity is evident on follow up imaging the signal abnormality was absent in the on admission mr imaging. Introductionwe report a case of hypertrophic olivary degeneration due to pontine hemorrhage. The proximal structures of the dtc pathway also form a segment of the guillain and mollaret triangle, a neural network which when disrupted causes hypertrophic olivary degeneration hod of the inferior olivary nucleus ion. Hypertrophic olivary degeneration is a rare form of transsynaptic degeneration and characterized by t2hyperintensity with or without enlargement of the inferior olivary nucleus. Frontiers hypertrophic olivary degeneration and palatal or.
Hypertrophic olivary degeneration hod is a rare condition characterized by a unique pattern of transsynaptic degeneration. T2 hyperintense non enhancing lesion that is accompanied by enlargement of the olivary nucleus, particularly if bilateral and symmetric, as our patient, can be explained only by hypertrophic olivary degeneration. T2 hyperintensity and enlargement of the inferior olivary nucleus ion are the radiological hallmarks of this entity. Track density imaging of hypertrophic olivary degeneration. In vertebrates, the ion is known to coordinate signals from the spinal cord to the cerebellum to regulate motor coordination and learning. Hypertrophic olivary degeneration hod is a rare transsynaptic neuronal degeneration affecting the dentato. Brain fiber tracking was performed by using software version 4. Dti was performed in 10 patients diagnosed with hod. Idiopathic bilateral hypertrophic olivary degeneration. The triangle of guillain and mollaret is formed by the ipsilateral red nucleus, the inferior olivary nucleus ion, and the contralateral dentate nucleus. In the appropriate clinical setting, bilateral hypertrophic olivary degeneration may be a sensitive and specific indicator of posterior fossa syndrome. Fiber tractography showed decreased volume of the right central tegmental tract, supporting a diagnosis of hod. Hod was visible on mri within a median of 6 months after the neurosurgical. Hypertrophic olivary degeneration hod is a rare abnormality that is caused by a lesion in the guillainmollaret triangle in the brainstem.
Imaging features of hypertrophic olivary degeneration hypertrophic olivary degeneration hod is a unique form of transneuronal degeneration caused by a disruption of the dentatorubro olivary pathway, also known as the triangle of guillainmollaret. Reports about bilateral hypertrophic olivary degeneration of the inferior olivary nuclei are very limited, and the magnetic resonance imaging findings of hypertrophic olivary degeneration in wilson disease have. A case of hypertrophic olivary degeneration after resection. This is a functional pathway composed by neural connections between. Hypertrophic olivary degeneration genetic and rare diseases. Reports about bilateral hypertrophic olivary degeneration of the inferior olivary nuclei are very limited, and the magnetic resonance imaging findings of hypertrophic olivary degeneration in wilson disease have not yet been described to the best of our knowledge. Diffusion tensor imaging of guillainmollaret triangle in patients with hypertrophic olivary degeneration. Symptoms and treatment hypertrophic olivary degeneration. Mr imaging was performed in 11 patientseight with pontine tegmental hemorrhages ths and three with cerebellar hemorrhages in the dentate nuclei. The inferior olivary nucleus ion, is a structure found in the medulla oblongata underneath the superior olivary nucleus. Hypertrophic olivary degeneration hod occurs as a result of a lesion in the anatomical functional loop of the guillainmollaret triangle.
Hypertrophic olivary degeneration on magnetic resonance. A gliotic lesion in the region of dentate nucleus of right cerebellar hemisphere. Hypertrophic olivary degeneration is a rare condition characterized by a unique pattern of transsynaptic degeneration. Its hallmarks include hypertrophy of the olive with increased t2 signal. Hypertrophic olivary degeneration hod is associated with lesions within the dentorubro olivary pathway or guillainmollaret triangle and may be associated clinically with palatal tremor. Peter bouz, rafeek oj woods, and kamal rm woods department of neurological surgery, loma linda university medical center, usa. It represents the end result of a lesion that damages the neuronal connection between the dentate nucleus of the cerebellum, the contralateral red nucleus and the ipsilateral inferior olivary nucleus, a functional system also known as the guillainmollaret triangle. Guillainmollaret triangle, hypertrophic olivary degeneration, magnetic resonance imaging introduction hypertrophic olivary degeneration hod is a rare occurrence in which different pathological processes including enlargement and vacuolation of the neurons, demyelination of the white matter, and fibrillary gliosis of the inferior olivary nucleus take place. A lesion within the dentatorubro olivary pathway drop in the posterior fossa can cause secondary neurodegeneration of the inferior olivary nucleus. Hypertrophic olivary degeneration hod is a pathological phenomenon that occurs after injury to the dentatoolivary pathway. Bilateral hypertrophic olivary nucleus degeneration on.
The evolution of hod results in three distinct phases on magnetic resonance imaging depending on changing patterns of t2 hyperintensity blue line as well as olivary hypertrophy gray line. Pdf mr imaging evaluation of inferior olivary nuclei. It has characteristic imaging findings and temporal evolution. Hypertrophic olivary degeneration bmj case reports. Hypertrophic olivary degeneration hod is a transneuronal degeneration secondary to focal lesions involving the dentatorubral olivary pathway, also know as guillainmollaret triangle. Jan 30, 2015 hypertrophic olivary degeneration hod is seen following lesions in the guillainmollaret triangle. Here we report hod on brain magnetic resonance mr imaging in three patients with progressive mitochondrial syndromes in the absence of palatal tremor. Hypertrophic olivary degeneration hod is a rare neurological condition of transsynaptic degeneration caused by disruption of the dentatorubro olivary pathway, otherwise known as the guillainmollaret triangle.