ARtykuł ORYGINALNY / ORIGINAL RESEARCH ARTICLE Vertigo in cerebellopontine angle tumor Patients Zaburzenia równowagi u pacjentów z guzem kąta mostowo-móżdżkowego Paulina Zarębska-Karpieszuk, Robert Bartoszewicz, Katarzyna Pierchała, Kazimierz Niemczyk Department of Otolaryngology, Medical University of Warsaw Head of the department: Prof. Kazimierz Niemczyk Article history: Received: 10.10.2015 Accepted: 26.11.2015 Published: 15.12.2015 ABSTRACT: Cerebellopontine angle tumors are a group of tumors that originate from the posterior cranial fossa. Most of them are acoustic neuromas arising from the Schwann cell sheath of the vestibular branch of VIII cranial nerve. Those benign tumors usually present with unilateral hearing loss (53–57%), tinnitus (79–82%), and vertigo/imbalance (18–50%). The objective of this study was documentation-based evaluation of 53 out of 96 patients that received surgical treat- ment in the ENT Department of Medical University in Warsaw during the period from May 2012 to May 2014, with spe- cial consideration of vertigo/imbalance in relation to other symptoms. Statictical analysis has shown larger frequency of vertigo/imbalance in patients with mild to moderate hearing loss and positive corelation between the largest diameter of the tumor and the vestibular deficit in VNG (videonystag- mography). The corelation of vestibular deficit in VNG and imbalance symptoms was only estabilished in the group with intrameatal localization of the tumor (T1). KEYWORDS: acoustic neuroma, vestibular schwannoma, vertigo, imbalance; cerebellopontine angle tumor; symptoms STRESZCZENIE: Guzy kąta mostowo-móżdżkowego to wspólna nazwa szeregu nowotworów lokalizujących się w tylnym dole czaszki pomiędzy tylną powierzchnią piramidy kości skroniowej (z uwzględnieniem przewodu słuchowego wewnętrznego) a brzuszną powierzchnią mostu oraz dolną powierzchnią móżdżku. Najczęstsze zmiany lokalizujące się w tej okolicy to osłoniaki części przedsionkowej n. VIII (Vestibular Schwannoma). Te łagodne, rzadkie w strukturze guzy wywołują zespół kąta mostowo-móżdżkowego. Ich charakterystycznymi objawami są: postępujący jednostronny niedosłuch odbiorczy (53–57%), szum uszny (79–82%), zawroty głowy (18–50%). Celem pracy było opracowanie profilu pacjentów z guzem kąta mostowo-móżdżkowego zakwalifikowanych do lec- zenia operacyjnego w Klinice Otolaryngologii WUM, a także analiza występowania w badanej grupie zaburzeń równowagi w odniesieniu do innych objawów. Dane pozyskano na podstawie retrospektywnego opracowania 53 historii chorób 96 pacjentów operowanych od maja 2012 r. do maja 2014 r. Analizie w programie Statistica poddano: maksymalny wymiar guza w osi PSZ, zaawansowanie guza w skali Koos’a i Perneczky’ego, ubytek słuchu według skali Gardnera-Robertsona, uszkodzenie narządu przed- sionkowego (na podstawie badania VNG), oraz występowanie zawrotów głowy w wywiadzie. Analizując wyniki, stwierdzono wyższą częstotliwość występowania zawrotów głowy u pacjentów z dobrze zachow- anym słuchem, a także dodatnią korelację pomiędzy wymiarem guza a patologicznym wynikiem VNG. Występowanie zaburzeń równowagi w wywiadzie współistniało z patologicznym wynikiem VNG tylko w grupie pacjentów z guzami wewnątrzprzewodowymi w stadium zaawansowania T1 wg Koos’a i Perneczky’ego. SŁOWA KLUCZOWE: nerwiak nerwu słuchowego, guzy kąta mostowo-móżdżkowego, zaburzenia równowagi, zawroty głowy, objawy guza kąta mostowo-móżdżkowego POLSKI PRZEGLĄD OTORYNOLARYNGOLOGICZNY, TOM 4, NR 4 (2015), S. 27-31 DOI: 10.5604/20845308.1184568 27 ARtykuł ORYGINALNY / ORIGINAL RESEARCH ARTICLE INTRODUCTION Cerebellopontine angle tumor is a common name for the who- le group of neoplasms located in the posterior cranial fossa between the rear surface of the petrous part of the tempo- ral bone, including the internal auditory meatus, and ventral surface of the pons and lower surface of the cerebellum. This region is the starting point for cranial nerves from VII to XII [1]. The greatest significance for consideration of pathology in the abovementioned region has facial nerve (cranial nerve VII) running with intermediate nerve and vestibulocochlear nerve (cranial nerve VIII) located laterally to it. From the star- ting point below the middle cerebellar peduncle and above the upper margin of the olive, a functional division of the cranial nerve VIII into its vestibular part starting with the upper root and cochlear part containing fibres from the lower root appro- Fig. 1. Distribution of patients with (1) and without (0) vertigo in relation to aching the inferior cerebellar peduncle is visible. The vestibular hearing impairment according to the Gardner-Robertson scale (AT- part is then divided into an upper branch (ramus superior) le- average tone) ading afferent fibers from the utriclenervus ( utriculo-ampul- laris) and a lower branch (ramus inferior) leading fibers from headaches, vomiting and disturbances of consciousness. These the saccular macula (nervus sacculo-ampullaris). The cochlear are directly related to oppression or indirectly to an increase part is the same as the cochlear nerve (nervus cochleae) and is in intracranial pressure. the most prone to damage nervous structure passing through the internal auditory meatus [2]. For the past few years a gradual shift of approach to treatment of cerebellopontine angle tumors has been observed. According Most common changes located in the cerebellopontine angle are to research by Stangerup and Caye-Thomasen [3] from 2012 schwannomas of the vestibular part of cranial nerve VIII. They for the past 40 years almost a threefold increase in cases dia- constitute more than 80% of cerebellopontine angle tumors and gnosed annually has been reported. It results from the develop- about 6% of all intracranial tumors. These are rare and benign ment of diagnostic methods including MRI as a gold standard tumors developing from Schwann’s myelin sheath, most often in diagnosing posterior fossa tumors, more widespread specia- vestibular part of the vestibulocochlear nerve, occasionally fa- lized healthcare facilities and increasing social awareness. At cial or cochlear nerve and the incidence rate is approximately the same time the mean size of diagnosed tumors decreased 1-10 cases per 1 000 000 population/year [3-5]. A characteristic from about 30 mm to 10 mm [3]. This tendency, combined place of their origin is so called Redlich-Obersteiner’s zone that with therapeutic decisions aimed not only at radical removal is the most medially located sections of the nerve covered in the of the illness but also at preservation of possibly high quality Schwann’s sheath where it comes into contact with glial frame- of life (QoL) motivates further teams to determine factors in- work protecting nerve fibers {Janczewski, 2007, Otolaryngolo- fluencing the rate of growth of newly-discovered tumors and gia Praktyczna}[4, 6]. Schwannomas are in prevalent proportion facilitating the choice of the optimal therapeutic option [9]. isolated (sporadic) and discovered in the fifth and sixth decade of life. Multiple, bilateral tumors coexisting with meningioma The best-studied parameter so far which may suggest refra- are correlated with genetically caused neurofibromatosis type ining from observation of small tumors (< 15-20 mm) and 2 and due to an early manifestation of symptoms they are typi- attempting radiotherapy or removal by microsurgery may be cally diagnosed between the second and third decade of life [7]. their growth rate within the first year of diagnosis. Yet this is not a sufficient factor to influence the decision, which is -sup Irrespective of the structure from which a given tumor origi- ported by great discrepancies between results provided by va- nated, the direction and rate of its growth determine charac- rious authors. Even though majority of researchers agree that teristic clinical manifestation which includes: progressive uni- a mean annual growth rate of tumor is 0.9-1.9 mm in the axis lateral sensorineural hearing loss (53-57%), tinnitus (79-82%), of the internal auditory meatus [9, 10], research by Stangerup vertigo (18-50%) and much less often facial or trigeminal nerve and Caye-Thomasen cited above revealed that within the first dysfunction [8]. Large tumors oppressing the brainstem and year of observation more than 60% of tumors increased their IV ventricle cause typically neurosurgical symptoms such as size by 10.3 mm on average. It did not necessarily advocate for 28 WWW.OTORHINOLARYNGOLOGYPL.COM ARtykuł ORYGINALNY / ORIGINAL RESEARCH ARTICLE Medical University of Warsaw between 05.2012 and 05.2014 was analyzed. A selected group of 53 patients underwent the final analysis: 31 females and 22 males aged 20 to 74 years (mean 47.3). Comparisons were made based on: sex, age, tumor size, stage in the Koos-Perneczky’s scale, hearing loss in the Gard- ner-Robertson scale, presence of facial nerve paralysis, history of vertigo, and vestibular deficit in VNG testing. RESULTS A mean tumor size was 15.78 mm (largest 40 mm, smallest 4.6 mm). According to Koos-Perneczky’s scale a tumor stage of T1 was found in 13 cases (24.5%), T2 stage in 25 (47%), T3 stage in 11 (21%) and T4 (7.5%) in 4. Fig. 2. Patients with (1) and without (0) vertigo in relation to tumor staging according to the Koss and Perneczky’s scale (t1-t4) Patients’ hearing directly before the operation was evaluated with the use of the Gardner-Robertson scale: group 1 (hearing ability within 0-30 dB, speech discrimination score >70%) inc- a need of surgical intervention because in the fourth