vestibular schwannoma

Cognitive Symptoms of Vestibular Schwannoma

admin — Wed, 15 Jul 2020 19:56:40 +0000

Cognitive Symptoms of Vestibular Schwannoma admin Wed, 07/15/2020 - 15:56

Acoustic neuroma, also known as vestibular schwannoma (VS), is the most common tumor that occurs in a region between the brainstem and inner ear, called the cerebellopontine angle or CPA. This region contains the nerves of hearing, balance, and facial movement.

The symptoms of VS vary but the most common are hearing loss and tinnitus. Other possible symptoms are imbalance, taste disturbance, headache, facial weakness, and/or facial numbness. Some tumors do not cause any symptoms and are found incidentally. In our experience, a not insignificant number of patients will also describe cognitive difficulties such as slow-thinking, memory lapse, or a non-specific “brain fog”. These can be some of the most troubling symptoms affecting patients with VS, but unfortunately, less is known about them because these symptoms can be vague and are also common in the general population.

Fortunately, research into these cognitive symptoms is increasing. While the exact prevalence of detectable cognitive impairment in VS patients is still unknown, recent studies of patients with various cerebellar tumours have shown that most patients were found to have deficits in at least one area of cognitive functioning,*1,2 and a constellation of deficits (including cognitive and emotional symptoms) as part of a “cerebellar syndrome” has been described. Fortuitously, existing research suggests that most patients see improvement in cognitive function with surgery.*1,3 It should be noted that most of this research is not specific to VS, or even tumors in the CPA, but comes from research on cerebellar tumors in general. Thus, we should be judicious in applying it to patients with VS.

Cognitive symptoms can affect patients with untreated tumors or after treatment with surgery or radiation. Although the exact incidence of development of new symptoms after treatment is unknown, they may be common and transient after treatment. Occasionally, new or pre-treatment symptoms persist; in one study of patients who underwent surgery for VS, 7% of patients self- reported long-term difficulty concentrating in an open-ended questionnaire.*4

At the University of Cincinnati Medical Center, we have begun to utilize biofeedback therapy for patients with cognitive symptoms. We will publish our results in the near future. In summary, cognitive symptoms can be very troubling to patients with vestibular schwannoma but remain poorly understood compared to other symptoms. Most of our existing knowledge comes from research of other types of tumors that affect the cerebellum or CPA, which suggests cognitive symptoms may be more common than realized.

References

1. Bodranghien F, Bastian A, Casali C, et al. Consensus Paper: Revisiting the Symptoms and Signs of Cerebellar Syndrome. Cerebellum. 2016;15(3):369–391.

2. Goebel S, Mehdorn HM. A missing piece? Neuropsychiatric functioning in untreated patients with tumors within the cerebellopontine angle. J Neurooncol. 2018;140(1):145–153.

3. Manto M, Mariën P. Schmahmann’s syndrome—identification of the third cornerstone of clinical ataxiology. Cerebellum Ataxias. 2015;2:2.

4. Bateman N, Nikolopoulos TP, Robinson K, O'Donoghue GM. Impairments, disabilities, and handicaps after acoustic neuroma surgery. Clin Otolaryngol Allied Sc 2000;25(1):62–65.

This article which appeared in ANA NOTES June 2020 is reprinted with permission of the authors and our US sister organization, ANA.

Ravi N. Samy, MD, FACS; Mario Zuccarello, MD, FACS; Scott B. Shapiro, MD; Noga Lipschitz, MD; Allie Mains, FNP, CNRN; University of Cincinnati Medical Center

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vestibular schwannoma

Patient Decision-Making in Vestibular Schwannomas

admin — Fri, 15 May 2020 19:30:36 +0000

Patient Decision-Making in Vestibular Schwannomas admin Fri, 05/15/2020 - 15:30

A collaborative study between the University of California, Irvine Neurotology and Skull Base Surgery Division and the Acoustic Neuroma Association was recently published in the journal Otology and Neurotology. The survey was completed by 789 members of the ANA, allowing surgeons to better understand the critical decision-making process patients use in choosing surgery, radiation, or observation.

It was determined that of the 789 participants, 629 (80%) saw multiple AN specialists and 410 (52%) sought second opinions within the same specialty.

Of those who received multiple consults, 242 (59%) of patients reported receiving different opinions regarding treatment. Those who elected to choose observation instead of intervention spent significantly less time with the physician (41 minutes) compared to surgery (68 minutes) and radiation (60 minutes) patients.

A total of 32 (4%) patients stated the physician alone made the decision for treatment, and 29 (4%) felt they did not understand all possible treatment options before a final decision was made. Of the 414 patients who underwent surgery, 66 (16%) felt they were pressured by the surgeon to choose a surgical treatment. It is common for AN patients to seek second opinions from physicians of different specialties and within the same specialty. Our findings demonstrate that those who seek second opinions have higher satisfaction rates as well. Thus, physicians should facilitate and help patients seek second opinions to better understand the various treatment modalities that can be offered.

80%

Percentage of patients in sample who saw multiple AN specialists for an opinion.

52%

Percentage of patients in sample who sought second opinions within same specialty.

59%

Percentage of patients who received different opinions from doctors about treatment.

Dr Hamid Djalilian

Hamid Djalilian, M.D is Director of Otology, Neurotology, and Skull Base Surgery Department of Otolaryngology – Head and Neck Surgery University of California, Irvine. Prior to UC Irvine, he was on the faculty at the University of Illinois, Cedars Sinai Medical Center, and UCLA. Dr. Djalilian's areas of expertise include complex ear surgery, hearing loss, balance disorders, facial nerve paralysis, and skull base surgery.

vestibular schwannoma

Understanding Vertigo in Vestibular Schwannomas

admin — Fri, 06 Apr 2018 21:52:51 +0000

Understanding Vertigo in Vestibular Schwannomas admin Fri, 04/06/2018 - 17:52

A Quality of Life Issue

The cardinal symptoms of vestibular schwannoma are unilateral hearing loss, tinnitus, vertigo, and unsteadiness. Most patients present with unilateral hearing loss (94%) and tinnitus (83%). Vestibular symptoms such as spinning vertigo, nausea, disequilibrium and imbalance have often been reported as mild, but are nevertheless present in 40 to 75% of patients. There is however remarkable variability in vertigo symptom severity and impact among patients. Several factors could explain this variability including the size of the tumour, the rate of growth, the rate of vestibular loss and the patients’ overall premorbid functioning level.

Recent studies focusing on quality of life associated with vestibular schwannoma have shown that when present, vertigo is the most debilitating and distressing symptom with respect to health-related quality of life. It also constitutes a risk factor for future work disability. While the subjective extent of impairment by vertigo is quite low initially, it could change considerably after intervention (surgery or radiation).

Why is there vertigo?

As humans, we orient ourselves in space with the input of our senses (vision, proprioception and vestibular function) integrated at the level of our central nervous system. The differential diagnosis of dizziness is therefore very broad.

The general complaint of «dizziness» is divided into four subtypes with different underlying etiologies: vertigo, disequilibrium, presyncope and psychological dizziness. Vertigo is a false sensation of movement of oneself or the environment. Disequilibrium is a sense of postural imbalance associated with a loss of balance that can relate to issues with the musculoskeletal system and proprioception. Presyncope is a feeling of faintness while psychological dizziness is typically related to anxiety or mood disorders. Vertigo can originate from a peripheral or central unilateral, asymmetric impairment of the vestibular system that causes an illusory sensation of movement.

The peripheral vestibular apparatus includes three semicircular canals, the utricle, saccule and the vestibular nerves. The central vestibular system comprises the vestibular nuclei, the brainstem, spinal cord, vestibular cortex and the cerebellum.

The role of the vestibular system is to help us maintain stable vision when the head is moving (through the vestibulocular reflex (VOR)) and to contribute to maintaining posture (through the vestibulospinal (VSR) and vestibulocolic reflexes (VCR)).

In the context of vestibular schwannoma, the tumour growth on one of the vestibular nerves affects the function of that nerve thus generating the asymmetry. It means that the vestibular reflexes (VOR, VSR and VCR) are impaired. Although acute changes of vestibular function can occur with vestibular schwannoma thus generating vertigo attacks with nausea, vomiting, lateropulsion to the lesioned side, and nystagmus to the contralesional side, the clear majority evolve so slowly that the changes of vestibular function are very subtle, and most patients do not experience severe a acks of vertigo. Vertigo is the presenting symptoms of only 10-15% of all vestibular schwannoma. More commonly, the patients with vestibular schwannoma might report symptoms of blurry vision for a split second when moving their head quickly toward the side of the lesion which is a sign of impaired VOR. They can also report a vague sense of imbalance and dizziness. Reports suggest that up to 75% of patients with vestibular schwannoma have some degree of vestibular symptoms.

As the tumor grows, it can put pressure on the brainstem and cerebellum thus generating more significant symptoms of dizziness and balance problems.

How does the approach to the management of vestibular schwannoma impact on vertigo?

The three commonly accepted treatment modalities for vestibular schwannoma include radiation therapy, microsurgery, and observation. Most studies comparing the different treatment approaches focus on comparing neurologic morbidity, hearing preservation and facial nerve function outcomes, all of which can be objectively assessed. Given that vertigo and dizziness are very subjective symptoms, the impact of treatment modalities on vertigo control is much more di cult to assess. A variety of scales and questionnaires have been designed to assess the extent and impact of vertigo (Dizziness Handicap Inventory (DHI, Vertigo Symptoms Scale (VSS), Short Form 36 Survey, Glasgow Benefit Inventory, etc.). None of these assessment tools is perfect as they all have their advantages and limitations. At the present time, while there is significant heterogeneity among small studies, there are no large-scale studies assessing vertigo symptoms systematically. It is therefore difficult to draw firm conclusions as to the impact of various treatment modalities on vertigo symptoms.

Smaller quality-of-life studies seem to suggest that surgery is associated with an increase in impairment of QOL by vertigo in the post-operative period. One study has shown that 31% of patients have disequilibrium lasting > 3 months after surgical removal of an acoustic neuroma. Worse outcomes were associated with age > 55.5 years, female gender, constant preoperative disequilibrium present for > 3.5 months, and central findings on electronystagmography.

Depending on the surgical approach, post-operative dizziness could be related to the extent of cerebellar retraction (retrosigmoid approach), and the loss of any residual vestibular function spared by the schwannoma. Because this change happens acutely at the time of surgery, vertigo is more readily perceived by the patient. Pre-operative vestibular function does impact the perceived dizziness after surgery. Therefore, someone who has had a slowly growing acoustic neuroma on one vestibular nerve and then has undergone surgical removal of the neuroma may exhibit almost no vestibular symptoms because the progressive and complete vestibular loss has already been compensated for progressively as the neuroma grew. By the time the surgery takes place, the patient has no effective vestibular function in the affected ear and the surgery could not worsen it further.

Because there is heterogeneity in the extent of vestibular function pre-operatively, there is a lot of variability among patients’ postoperative dizziness symptoms. Conversely, radiation therapy seems to be associated with lower rates of vestibular symptoms in the acute post-treatment period. Given that the impact of radiation can be felt for years after the treatment, some studies suggest an increase in dizziness in the years after treatment.

Treatment of Vertigo: What is vestibular physiotherapy and how does it work?

Regardless of the treatment approach to vestibular schwannoma, significant vertigo symptoms can be present and impact the patients’ quality of life. Specifically targeting these vertigo symptoms and overall balance is an important component of the care provided to patients with vestibular schwannoma. Given that regaining vestibular function on the tumor side is not possible, the therapeutic approach focuses mainly on optimizing compensation for this unilateral vestibular loss through vestibular physiotherapy.

Both animal and human studies emphasize the importance of early ambulation with head and neck mobilization in the first four post-operative days. Mobilization in this crucial period of recovery has a significant impact on the course of vestibular compensation. Encouragement and reassurance are needed at that time since patients might feel quite dizzy during this acute post-operative period and be very reluctant to move. Antiemetics and vestibular suppressants can be used to control nausea in this acute setting but should not be used long-term as they hinder the compensation process.

Vestibular compensation encompasses a variety of centrally mediated mechanisms that help us achieve vision and postural control despite the lack of vestibular input. At the level of the brainstem and cerebellum, the activity of the vestibular nuclei is modulated but the impact on maintaining the vestibular re exes is marginal. Compensation happens mainly through input substitution and learned anticipatory adjustments which can be trained.

The loss of vestibular function from one ear leads to increased reliance on vision and somatosensory information to perceive self-motion, orient the body, stabilize the head and control the center of mass. For instance, instead of the VOR, vision is stabilized though anticipated covert eye movements (saccades) that happen during the head movement.

Through a variety of exercises centered on stabilizing vision and maintaining balance while the head is moving, and the body is in motion, vestibular physiotherapy triggers the development of these alternative compensatory mechanisms. In the initial postoperative period, these exercises can feel as if they trigger the vertiginous symptoms because they bring out the vestibular deficit. This is the stimulus necessary for the brain to engage the compensatory mechanisms. With time and effort, desensitization to the symptoms and compensation occur while a more robust balance is achieved, all contributing to decreased vertigo and disequilibrium.

Dr Mijovic

Tamara Mijovic MD CM FRCSC is an assistant professor of Otolaryngology-Head and Neck Surgery at McGill University.

As a fellowship trained Otologist and Neurotologist, she is the director of the McGill University Health Center (MUHC) Vestibular Laboratory and an active lateral skull base surgeon part of the multidisciplinary Skull Base Surgery Team at the Jewish General Hospital.

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