Posterior reversible encephalopathy syndrome presenting as Balint syndrome

Optic ataxia in a patient with HaNDL syndrome

We present a woman in her 40s who arrived at the emergency room with hypertension and optic ataxia. Her medical history is only relevant for obesity. Her lumbar puncture revealed high intracranial pressure and lymphocytic pleocytosis, and her neuroimaging tests, including angiography and venography, were normal. The patient improved after a cerebrospinal fluid drainage with a lumbar puncture, and her clinical manifestations resolved in parallel to the lymphocytic pleocytosis.The patient was diagnosed with a syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis and fully recovered 21 days after her discharge.

Higher Cortical Visual Disorders

PURPOSE OF REVIEW

This article reviews the disorders that result from disruption of extrastriate regions of the cerebral cortex responsible for higher visual processing. For each disorder, a historical perspective is offered and relevant neuroscientific studies are reviewed.

RECENT FINDINGS

Careful analysis of the consequences of lesions that disrupt visual functions such as facial recognition and written language processing has improved understanding of the role of key regions in these networks. In addition, modern imaging techniques have built upon prior lesion studies to further elucidate the functions of these cortical areas. For example, functional MRI (fMRI) has identified and characterized the response properties of ventral regions that contribute to object recognition and dorsal regions that subserve motion perception and visuospatial attention. Newer network-based functional imaging studies have shed light on the mechanisms behind various causes of spontaneous visual hallucinations.

SUMMARY

Understanding the regions and neural networks responsible for higher-order visual function helps the practicing neurologist to diagnose and manage associated disorders of visual processing and to identify and treat responsible underlying disease.

Ocular Dysfunctions Presenting in Tacrolimus-Induced Posterior Reversible Encephalopathy Syndrome: A Case Presentation

The constellation of ocular symptoms known as Balint syndrome is a rare disorder seen in bilateral parieto-occipital lesions and is most frequently due to arterial occlusive disease or acute hypertension. Here we present the case of a patient with tacrolimus-induced posterior reversible encephalopathy syndrome (PRES) who presented with optic ataxia, simultanagnosia, and ocular apraxia. These ocular findings, consistent with Balint syndrome, are rarely the initial presentation of PRES. This case highlights the importance of early recognition of this unusual phenomenon, as well as the importance of an individualized rehabilitation plan to maximize functional independence in these patients.

LEVEL OF EVIDENCE

V.

Posterior Reversible Encephalopathy Syndrome due to High Dose Corticosteroids for an MS Relapse

Increased blood pressure is a known adverse effect associated with corticosteroids but little is published regarding the risk with the high doses used in multiple sclerosis (MS). A 53-year-old female with known relapsing remitting MS presented with a new brainstem relapse. Standard of care treatment for an acute MS relapse, 1250 mg of oral prednisone for 5 days, was initiated. She developed an occipital headache and dizziness and felt generally unwell. These symptoms persisted after treatment was complete. On presentation to medical attention, her blood pressure was 199/110 mmHg, although she had no history of hypertension. MRI changes were consistent with posterior reversible encephalopathy syndrome (PRES), demonstrating abnormal T2 signal in both thalami, the posterior occipital and posterior parietal white matter with mild sulcal effacement. As her pressure normalized with medication, her symptoms resolved and the MRI changes improved. No secondary cause of hypertension was found. This is the first reported case of PRES secondary to high dose corticosteroid use for an MS relapse without a history of hypertension and with no other secondary cause of hypertension identified. This rare complication should be considered in MS patients presenting with a headache or other neurological symptoms during treatment for a relapse.

Optic ataxia: from Balint's syndrome to the parietal reach region

Optic ataxia is a high-order deficit in reaching to visual goals that occurs with posterior parietal cortex (PPC) lesions. It is a component of Balint's syndrome that also includes attentional and gaze disorders. Aspects of optic ataxia are misreaching in the contralesional visual field, difficulty preshaping the hand for grasping, and an inability to correct reaches online. Recent research in nonhuman primates (NHPs) suggests that many aspects of Balint's syndrome and optic ataxia are a result of damage to specific functional modules for reaching, saccades, grasp, attention, and state estimation. The deficits from large lesions in humans are probably composite effects from damage to combinations of these functional modules. Interactions between these modules, either within posterior parietal cortex or downstream within frontal cortex, may account for more complex behaviors such as hand-eye coordination and reach-to-grasp.

Balint syndrome

We report a patient who presented with complaints of blindness following stroke and was subsequently diagnosed to have Balint syndrome.