Treatment of chronic canalithiasis can be beneficial for patients with vertigo/dizziness and chronic musculoskeletal pain, including whiplash related pain

2.1 Diagnostic criteria

1. The diagnosis of canalithiasis is confirmed with the following:

   1. Specific history of vertigo or dizziness provoked by acceler-ation or deceleration AND.

   2. Nystagmus and symptoms during at least one of the test positions.

2. The disorder had persisted for at least one year.

2.2 Exclusion criteria

1. Consequent smooth pursuit eye movement ataxia, i.e. uni- or bilateral ocular ataxia characteristic for a CNS disorder (pontine or cerebellar lesion).

2. Saccadic eye movement test disturbance, especially hyper- or hypometric, which is characteristic for CNS disorders such as multiple sclerosis.

3. Migraine (confirmed by positive effect of migraine specific medication).

4. Active Ménière’s disease.

5. Severe eye disorders, i.e. conditions where optimal vision cannot be obtained by optical aids.

6. Cardiovascular disorder.

7. Pain caused by cancer or rheumatic diseases.

8. Severe elevated body mass index.

2.3 Procedure

2.3.3 Diagnosing procedure

The two first authors performed the diagnosing procedure simultaneously. The tests were developed by the authors and based on their clinical experience. The nystagmus registration was done consecutively: (1) in sitting position; (2) in side-lying position, head turned 45° upwards; (3) in sitting position again. Two minutes were spent in each position. We refrained from using the Dix-Halpike test, since the majority of the patients in this study group suffered from severe neck pain. We wanted to avoid exacerbationoftheir pain. The nystagmus was registered byvideo-oculography (Interacoustics A/S, Assens, Denmark). Oculography is superior to oculoscopy as it is able to register the lowest amplitude nystagmus. The cause of canalithiasis is believed to be otoliths or debris, which have loosened from macula utriculi and moved into one or more semicircular canals (SCCs) in the vestibule of the inner ear. It can be difficult to move solid floating particles in liquid by rapid movements; therefore the repositioning manoeuvres were done in slow motion. Because of the possible long latency before nystagmus was evoked in some patients, they were kept for 2min in each position during the diagnostic procedure (Stoke’s law). Otoliths in one SSC give a specific nystagmus pattern. Otoliths in more than one SSC give various nystagmus patterns depending on how many SSCs are activated and the amount of debris present. Divergence from one-SSC pattern was interpreted as a canalithiasis with otoliths in more than one SSC [13]. The criterion for diagnosing otoliths in the anterior SCC is a downbeat/torsio or eventually an isolated downbeat nystagmus in one of the test positions [14]. However, in patients with unilateral canalithiasis involving all three SCCs, we observed torsio/upbeat in the ipsilateral position and up or downbeating nystagmus in the contralateral position (Fig. 1). An analytic nystagmus study as well as a smooth pursuit eye movement study on this material of patients with chronic canalithiasis will follow in a separate publication.

Fig. 1

Video-oculographic documentations of BPPV. (1) Demonstrates an affection of the posterior SCC in the left labyrinth. The patient is lying on his left side; his head turned 45° up. The rectangle shows the last 20s of a 30s sequence. At the right side of each rectangle the quantitative details are given, i.e., the counts of nystagmus and their orientation (left, right, down and up) during a 30s period, beats per second, and SPV, i.e., Slow Phase Velocity of nystagmus beats. This patient had 20 left-directed horizontal nystagmus beats and 30 up-right vertical nystagmus beats. (2) Demonstrates the nystagmus appearance after coming back into an upright position. Now the horizontal nystagmus beats are dominant and this is interpreted as a possible horizontal SCC affection. (3) Demonstrates an affection of the anterior SCC in the left labyrinth. The patient is lying on his right side; his head turned 45° up. The patient had 39 up-right directed vertical nystagmus beats and six right horizontal directed nystagmus beats. (4) Demonstrates the nystagmus appearance after returning into an upright position. There are now very few nystagmus beats. The video-oculographic picture was interpreted as a multicanalicular canalithiasis with an affection of the anterior and posterior SCCs as well as a possible affection of the horizontal SCC in the left labyrinth. The recordings are from a 52 year old man with a 2 year history of neck pain and fatigue after a road traffic accident. The patient received repositioning of otoliths in all three SCCs, left side, and he improved significantly.

Polensek and Tusa in 2009 found the caloric test unnecessary for diagnosing BPPV [15]. The caloric test and the head impulse test were excluded in this study because they do not give reproducible results in patients with BPPV. This is because the otoliths in the SCC are influenced by the slightest movement and the latency and nystagmus duration are variable. The oculomotor test battery (i.e. smooth pursuit eye movement test and saccadic eye movement test) has been applied to exclude patients with CNS disorders.

3.1 Patients with the diagnosis of chronic canalithiasis and chronic pain

Forty-seven patients with chronic pain (WAD, fibromyalgia, myalgia etc.) who suffered from a chronic canalithiasis fulfilled the diagnostic criteria. Two patients were excluded, one with multiple sclerosis and one due to parallel treatment at another institution. Forty-five patients received the follow-up questionnaire. The responders constituted the study group. Thirty-nine responded (87%) (8 males and 31 females) with a median age of 44 years (range 17–65; quartiles 39–52). The median durationof the disease was 5 years (range 1–36; quartiles 4–16). The median number of otolith repositioning manoeuvres done was six (range from2to29; quartiles 4–9.5). Median time span between finishing the otolith repositioning manoeuvres and answering the questionnaire was 7 months (range 1–31; quartiles 3–15).

3.2 Trauma

Thirty-one patients (79%) had a history of head or neck trauma resulting from road traffic accidents, fall accidents, or sports injuries.Sixteenpatients (41%) ful filled the Quebec Task Force criteria for the diagnosis of whiplash associated disorders (WAD) [18]. Fifteen individuals (38%) had a history of trauma without continuous symptoms for a period of time after the accident. The majority of these believed that their disorder was a result of the previous trauma. Eight (21%) could not recall any trauma. There was no difference in age, gender and duration of illness among those with and without trauma. There was also no difference inDHI-score, frequency of symptoms, number of otolith repositioning manoeuvres or treatment results.

3.3 Vertigo

Twenty-one (54%) individuals suffered from nautical vertigo and dizziness, two (5%) from isolatedrotatory vertigo, and sixteen (41%) from combined rotatory vertigo and nautical vertigo/dizziness see Table 1.

The Dizziness Handicap Inventory (DHI) median score was 48 points (range 20–72; quartiles 38–60).

3.4 Nystagmus

The video-oculography confirmed canalithiasis in more than one semicircular canal in all patients. Ten patients (26%) had isolated upbeat- or downbeat vertical nystagmus. In the present study more patients had upbeat nystagmus than downbeat (Fig. 1). Nineteen individuals (49%) had minimal improvement after repositioning of otoliths in posterior and horizontal SCCs. These nineteen patients had no isolated vertical nystagmus, but were treated for an anterior SCC canalithiasis.

There were no differences in treatment outcome between patients with and without isolated vertical nystagmus. Thus, inthis study the frequency of affected anterior SCC was at a minimum of 26% and could be as high as 65%.

3.5 Pain

Thirty-seven patients (95%) suffered from headache, thirty-six (92%) from neck pain, twenty-one (54%) from generalized pain, and twenty-two (56%) from temporo-mandibular joint (TMJ) region pain. Nineteen out of the twenty-two patients with TMJ region pain underwent treatment for otoliths in the anterior SCC, and thirteen out of these nineteen patients reported resolution of TMJ region pain after treatment.

A report from a patient with TMJ region pain: “After you turned me upside down in the chair my life changed. The TMJ region pain and the headache disappeared and so did the hard pressure around my head. I got very tired for some days. After treatment my life went from night to day. I really appreciate the help I got. I was told at the neurological department at the hospital that my pain and other symptoms were of psychological origin and psychophar-maca were prescribed, which I did not take. Instead I contacted you”.

This patient had no isolated vertical nystagmus, but it was alack of success by repositioning the otoliths in posterior and horizontal SCCs. Therefore, she was treated with a summersault manoeuvre.

3.6 Analgesic drugs used before and after otolith repositioning

Thirteen patients used no pain medication before treatment due to lack of amelioration or fear of addiction.

3.7 Other associated symptoms

Fatigue (97%), aggravation by physicalexertion (87%), decreased ability to concentrate (85%) as well as visual disturbances (85%) was the most frequent reported symptoms. Nausea was reported among 28 individuals, i.e. 72%. Twenty-four patients (62%) (5 males and 19 females) suffered from temperature disturbances (i.e. heat flush, profuse sweating or chills). Six females were below forty years of age. Nineteen (49%) suffered from tinnitus.Fourteen (36%) reported involuntary movements.

3.8 Follow-up

The answers from the patients are given in Table 3. Thirty-five patients (i.e. 90%) had some improvement or more. Four patients did not benefit from the treatment, although one reported initial substantial improvement, but relapsed after a couple of weeks. No patient reported disimprovement after treatment. Twenty-seven individuals, i.e. 59%, suffered at least one relapse.

Age, duration of sickness, DHI-score and follow-up time had no significant influence on the results.

4.1 Nautical vertigo, dizziness, pain and other associated symptoms

In the present study, patients with musculoskeletal pain were referred for physical therapy. Another group of patients with ver-tigo/dizziness were referred for otoneurologic investigations [9]. All patients in both groups had a DHI-score above 20 and were diag-nosed with a multiple-canal involvement chronic canalithiasis. The frequency of symptoms was similar in both series.

Due to the high response on the follow-up questionnaire, it is likely that the given answers are representative. The median time span between completed otolith repositioning manoeuvres and answering the questionnaire was 7 months. Half of the patients responded in the period of 3–15 months. Therefore, the possible placebo effect of treatment has probably been minimized. This assumptionis supported by lack of correlation between the follow-up time span and the given answers.

The present study has shown that repositioning of otoliths in the SCCs on patients with chronic canalithiasis ameliorates pain and other symptoms. The correlation between vertigo/dizziness and the majority of symptoms was significant. Temperature dis-turbance, involuntary movements and TMJ-pain had a tendency to be statistically correlated. Therefore, the present study supports the former statement [9] that there is a likely connection between chronic canalithiasis and the following symptoms: nautical vertigo/dizziness, neck pain, headache, generalized pain, fatigue, visual disturbances, cognitive dysfunctions, nausea, and tinnitus.

4.2 Dynamic- and not static balance disturbance

Patients with BPPV and Ménière’s disease, who have a dynamic balance disturbance, do not improve by exercises to compensate like patients with a static balance disturbance, e.g. vestibular neuritis [19, 20,21]. It is impossible to compen sate in the same way within a canalithiasis with its dislocated free-floating otoliths and debris, because the affected labyrinth (s) transmit (s) varying abnormal sig-nalsfrom timetotime to the samestimuli. This is possibly why their symptoms are ongoing [9].

4.3 Trauma

Trauma seems to be a main cause of chronic canalithiasis. The frequency of patients with a history of trauma was the same in both study groups, i.e. the present pain-related- and the former vertigo-related study group [9]. Ernst et al. (2005) [2] documented that there could be a time span between the trauma and the on set of symptoms. In both study groups all patients suffered from a multiple-canal involvement canalithiasis. Many studies have documented that traumatic chronic BPPV patients can be relative resistant to treatment [22,23,24,25,26,27,28]. We raise the question: is this because of an affection of the anterior SCC [14,27].

4.4 Anterior SCC and TMJ region pain

In the up right resting position, the anterior SCC is the only SCC where otoliths and debris will be placed on top of the cupula. Even the slightest movement of the head, e.g. walking, talking, eating, the cupula is affected. In the present study a high frequency of possible anterior SCC affection was found. The majority did not have the isolated vertical nystagmus, but they responded positively on the forward summersault manoeuvre used for treating the anterior SCC. Since all the patients suffered from a multicanalicular canalithiasis the observed nystagmus pattern differed from the ordinary findings in uni-canalicular canalithiasis. The most affected SCC dominates the nystagmus pattern, but the nystagmus pattern is also influenced from other affected SCCs. The huge difference between the observed frequency of affected anterior SCC in the present study compared to other studies may be explained by the fact that we studied patients with multi-canalicular canalithiasis while the other studies are based on uni-canalicular canalithiasis [13,14].

Half of the patients in the present study suffered from TMJ region pain, nearly all of them were treated for an anterior SCC BPPV. The majority responded positively. TMJ region pain is a common and unsolved problem among many patients with WAD [29,30]. The most common explanation is that the TMJ pain is due to the tension of the ligaments in the temporo-mandibular joint caused by translational force during the initial impact on the vehicle.

The relative high frequency of WAD in these series might be explained through the characteristic whiplash trauma, i.e. acceleration/deceleration. Otoliths are slung through a natural trajectory from the macula utriculi to the crus commune and further into the posterior and anterior SCCs.

During repositioning of otoliths in the anterior SCC, pain in the TMJ region (including otalgia) often occurred in the first position and then declined in the next. The motor root of the trigeminal nerve innervates the muscles of mastication (the masseter, temporalis, and pterygoides and a few muscles of the palate (tensor veli palatine), middle ear (tensor tympani), and upper neck (mylohyoid and anterior belly of digastric muscle) [31]. Nearly two thirds of the patients in the present study had resolution of pain in the TMJ region after otolith repositioning.

4.5 Vestibulo-cranial nerve reflexes

The mentioned symptoms (Table 1) can be explained through inappropriate activity in the vestibular reflexes [9]. Symptoms associated with the cranial nerves are observed appearing and dis-appearing during otolith repositioning manoeuvres like the TMJ region pain related to the trigeminal nerve [32]. Therefore, it is not out of the question that there are reflexes from the vestibular nuclear complex to other cranial nerves than the oculomotor nerves (III, IV, VI). Together with nystagmus during otolith repositioning, many patients have periorbital clonic spasms, which we have interpreted as facial nerve activity. We have as well observed and palpated clonic spasms in the sternocleidomastoid and trapezius muscle innervated by the accessory nerve.