Microvascular decompression for spasmodic torticollis

[Historical view on the pathogenesis and surgical treatment of cervical dystonia]

In the past few decades, approaches to surgical treatment of dystonia passed through paradigmatic shift. Intradural upper cervical anterior rhizotomy was replaced by selective peripheral denervation with lesser spectrum of side-effects. Such techniques as microvascular decompression of accessory nerve or spinal cord stimulation for cervical dystonia were abandoned due to lack of proven efficacy. Introducing globus pallidus interna (GPi) DBS in 1990's to treat all types of dystonia, including cervical dystonia, was a fundamental factor. With the growing body of knowledge on the pathophysiology of dystonia, GPi DBS appears to be the most expedient, effective and safe method with limited indications to peripheral destructive procedures.

Microvascular decompression with partial occipital condylectomy in a case of pediatric spasmodic torticollis

Spasmodic torticollis is a rare, neurologic disorder that is caused by abnormal nerve compression of the 11th cranial nerve by blood vessels or bony protrusions. It is typically treated pharmacologically and, if necessary, with surgical intervention. We report a unique case of spasmodic torticollis in a 15-year-old female that involved abnormal compression of the left 11th cranial nerve (CN) by the left vertebral artery, displaced by a hypertrophic left occipital condyle. After treatment with Botox was unsuccessful, the patient was treated with microvascular decompression and occipital condylectomy that adequately relieved the abnormal compression of CN XI. Mild symptoms persisted, and the patient underwent a partial section of the sternocleidomastoid muscle 1 year later, after which torticollis symptoms resolved.

Improvement of quality of life and mental health in patients with spasmodic torticollis after microvascular decompression

OBJECTIVE

Although not life threatening, spasmodic torticollis (ST) impairs patients' daily activity, socialization and work. The aim of this study was to evaluate the quality of life (QOL) and mental health in patients with ST after microvascular decompression (MVD).

PATIENTS AND METHODS

From June 2014 to June 2017, patients with ST who underwent MVD in our department were included in this study. Toronto Western Sparse Torticollis Rating Scale (TWSTRS) were used to evaluate the ST symptoms. Quality of life was assessed by the craniocervical dystonia questionnaire (CDQ-24). Beck Depression Inventory (BDI-II) and Beck Anxiety Inventory (BAI) were used to evaluate the mental health. Intraoperative findings and follow-up results were analyzed.

RESULTS

A total of 104 consecutive patients were enrolled in this study. At the 12 months follow-up, the total effective rate was 81.73%. After MVD surgery, 88(84.62%) ST patients experienced QOL improvement. The severity of ST symptoms was positively correlated with the CDQ-24 score(r = 0.31, P = 0.02). Forty-eight patients (46.16%) with ST have moderate to severe depression and nine (8.65%) have depression preoperatively. Pain and disability domains of TWSTRS were found have high relation with BDI-II score(r = 0.27, P = 0.02; r = 0.33, P = 0.03). There was a positive correlation of educational levels with the BDI-II scores(r = 0.45, P = 0.02).

CONCLUSION

ST affects patients' QOL both physically and mentally. MVD for ST not only provides high spasm-relief rate but also leads to significantly higher QOL after surgery. Not only ST symptoms, but also psychiatric status of patients should be routinely followed. Psychological care and psychopharmaceuticals should also be considered for these patients.

New Rhizotomy Procedure for Primary Spasmodic Torticollis

OBJECTIVE

Spasmodic torticollis (ST) is an idiopathic neurologic disorder affecting the muscles of the neck. Surgery is a preferred treatment, when conservative treatments or Botulinum neurotoxin injections fail to relieve the symptoms. Our objective here is to report the outcome of a new surgical method for treating ST patients in our department.

METHODS

The new procedure consists of rhizotomy of the spinal accessory nerve (SAN) and C1-C2 nerve roots, coagulation of the distal end of SAN (Group A). The results of this procedure were compared with a group of patients who underwent only rhizotomy of the SAN and anterior C1-C2 nerve roots (Group B). Clinical data were retrospectively collected from 39 patients with laterocollis and rotatory torticollis subtypes of ST from Jun 1, 2014 to Jun 1, 2015. The effect of the surgery was evaluated by the reduction in the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) total scores preoperatively and postoperatively. The mean duration of the postoperative follow-up period was 2.57 years, ranging from 2 to 3 years.

RESULTS

The mean preoperative TWSTRS score was 65.89 ± 3.55 and 65.80 ± 3.45 in Groups A and B, respectively. Six months after the surgery, the TWSTRS scores decreased to 40.00 ± 12.14 and 26.04 ± 11.77, respectively. There was a statistically significant improvement preoperatively and postoperatively in both groups (P < 0.05). The decrease in TWSTRS score of Group B was more significant than that of Group A (P < 0.05). The main complications included shoulder numbness, shoulder weakness, and hoarseness.

CONCLUSIONS

The procedure in this study provides a new and effective surgical method for patients with ST. This procedure should be recommended if conservative therapy does not offer satisfactory relief of symptoms.

Comparison of 2 Operative Methods for Treating Laterocollis and Torticollis Subtypes of Spasmodic Torticollis: Follow-Up of 121 Cases

OBJECTIVE

The aim of this study was to compare the effects and complications of microvascular decompression (MVD) and neurectomy of spinal accessory nerve in the treatment of laterocollis and torticollis subtypes spasmodic torticollis (ST).

METHODS

Clinical data were retrospectively collected from 121 patients with laterocollis and torticollis subtypes of ST from January 1, 2012 to January 1, 2016. Among all the patients, 80 were treated by MVD and 41 were treated by neurectomy of spinal accessory nerve. The effect of the surgery was evaluated by the reduction in the Toronto Western spasmodic torticollis rating scale total scores before and after the operation. The mean duration of the postoperative follow-up period was 18.7 months (range, 12-27 months).

RESULTS

At the final follow-up, the Toronto Western spasmodic torticollis rating scale total score in the MVD group and in the neurectomy group was lowered by 50.43% ± 20.3% and 30.23% ± 19.4%, respectively, compared with the preoperative status (P < 0.05). In the MVD group, 25 (31.25%) patients achieved excellent relief, 44 (55%) patients improved moderate spasm, and 11 (13.75%) showed no relief. In the neurectomy group, 6 (14.63%) patients improved with excellent outcome, 7 (17.07%) had moderate relief, and 28 (68.29%) had no relief. There was no mortality or severe complication postoperatively, with the exception of hoarseness, shoulder numbness, and weakness.

CONCLUSIONS

MVD for ST of laterocollis and torticollis subtypes can provide satisfactory and lasting improvements without nerve impairment. MVD is to be preferred to neurectomy of accessory nerve in treating ST of laterocollis and torticollis subtypes.

Resolution of intractable retching following mobilization of a dolichoectatic vertebral artery: case report of a unique brainstem-cranial nerve compression syndrome

The authors present the case of a 53-year-old man who was referred with disabling retching provoked by left arm abduction. At the time of his initial evaluation, a cervical MRI study was available for review and revealed an anatomical variation of the ipsilateral juxtamedullary vertebrobasilar junction. After brain imaging revealed contact of the medulla by a dolichoectatic vertebral artery at the dorsal root entry zone of the glossopharyngeal and vagus nerves, the patient was successfully treated by microvascular decompression of the brainstem and cranial nerves. This case demonstrates how a dolichoectatic vertebral artery-a common anatomical variation that typically has no clinical consequence-should be considered in cases of cranial nerve dysfunction.

Presurgical evaluation of hemifacial spasm and spasmodic torticollis caused by a neurovascular conflict from AICA with 3T MRI integrated by 3D drive and 3D TOF image fusion: A case report and review of the literature

Background:

Hemifacial spasm (HS) and spasmodic torticollis (ST) are well-known disorders that are caused by a neurovascular conflict. HS is characterized by irregular, involuntary muscle contractions on one side of the face due to spasms of orbicularis oris and orbicularis oculi muscles, and is usually caused by vascular compression of the VII cranial nerve. ST is an extremely painful chronic movement disorder causing the neck to involuntary turn to the side, upward and/or downward. HS is usually idiopathic but it is rarely caused by a neurovascular conflict with the XI cranial nerve.

Case Description:

We present a case of a 36-year-old woman with a 2-year history of left hemifacial spasm and spasmodic torticollis. Pre-surgical magnetic resonance imaging MRI examination was performed with 3TMRI integrated by 3Ddrive and 3DTOF image fusion. Surgery was performed through a left suboccipital retrosigmoid craniectomy. The intraoperative findings documented a transfixing artery penetrating the facial nerve and a dominant left anteroinferior cerebellar artery (AICA) in contact with the anterior surface of the pons and lower cranial nerves. Microvascular decompression (MVD) was performed. Postoperative course showed the regression of her symptoms.

Conclusions

Transfixing arteries are rarely reported as a cause of neurovascular conflicts. The authors review the literature concerning multiple neurovascular conflicts.

Microvascular decompression surgery is effective for the laterocollis subtype of spasmodic torticollis: a long-term follow-up result

BACKGROUND

Spasmodic torticollis (ST) is characterized by sustained, involuntary, and painful spasms of specific muscle (s), which results into abnormal posture of the neck and head. Although various treatments for ST have been introduced, none of them shows absolute effectiveness. Earlier research from our department showed that microvascular decompression (MVD) surgery is effective in the short-term for ST patients with confirmed accessory nerve compression. However, the long-term outcome of MVD remains unknown.

METHOD

Twelve ST patients with confirmed accessory nerve compression received MVD surgery of their accessory nerves. We utilized the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) to evaluate the long-term outcome (5.4 ± 0.87 years).

RESULTS

The MVD lowered total TWSTRS scores by 42.8 % in all ST patients. This result, however, only counted for moderate relief. Interestingly, we observed that the laterocollis (LC) subtypes of ST (n = 3) obtained a higher TWSTRS score improvement (86.9 ± 6.2 %), compared to that of the non-LC (28.1 ± 12 %) (P =0.0001). Additionally, the disability (92.7 ± 2 %) subscale score in the LC subtypes had the most prominent improvement compared to the pain (88.1 ± 5.1 %) and severity (81.3 ± 10.5 %).

CONCLUSIONS

In the cases of confirmed accessory nerve compression, the MVD could be considered as a treatment alternative for ST, especially for the LC subtypes.

Type 2 diabetes mellitus: A central nervous system etiology

BACKGROUND

Insulin resistance (hyperinsulinemia) is said to be the signal event and causal in the development of type 2 diabetes mellitus. Pulsatile arterial compression of the right anterolateral medulla oblongata is associated with autonomic dysfunction, including "driving" the pancreas, which increases insulin resistance causing type 2 diabetes mellitus. In this prospective study, we hypothesize that decompressing the right cranial nerve X and medulla will result in better glycemic control in patients with type 2 diabetes mellitus.

METHODS

Ten patients underwent retromastoid craniectomy with microvascular decompression for type 2 diabetes mellitus. Patients were followed for 12 months postoperatively by blood glucose monitoring and studies of glycemic control, pancreatic function and insulin metabolism. No changes in diet, weight or activity level were permitted during the course of the project.

RESULTS

Seven of the 10 patients who received microvascular decompression for type 2 diabetes mellitus showed significant improvement in their glucose control. This was noted by measurement of diabetes markers and decrease of diabetes medication dosages. One patient was completely off diabetes medication, while attaining euglucemia. The other 3 patients did not improve in their glucose control. The body mass index of these 3 patients was higher (mean, 34.4) than those with better outcomes (mean, 27.9).

CONCLUSION

Arterial compression of the right anterolateral medulla appears to be a factor in the etiology of type 2 diabetes mellitus. Microvascular decompression may be an effective treatment for non-obese type 2 diabetes mellitus patients.

Microvascular decompression of the accessory nerve for treatment of spasmodic torticollis: early results in 12 cases

PURPOSE

To describe the early effectiveness of microvascular decompression (MVD) for the treatment of spasmodic torticollis (ST).

METHODS

Twelve patients with spasmodic torticollis were treated by microvascular decompression of the accessory nerves using a microscopic neurosurgical technique via the retrosigmoid approach. The most common compressing blood vessels were the ipsilateral posterior inferior cerebral artery (PICA) and/or the vertebral artery. The intraoperative monitor was introduced to detect the accessory nerve and to avoid unnecessary damage to the nerve.

RESULTS

Ten patients were cured (83%), and the other two (17%) improved with moderate spasms. In most cases, the improvement was noticed 1 week after the operation. No operation-related complications were observed during the follow-up period, which ranged from 2 months to 3 years.

CONCLUSIONS

The early effect of MVD for some patients with spasmodic torticollis was satisfactory, but the long-term results need to be assessed further.

POLYTETRAFLUOROETHYLENE-INDUCED GRANULOMA AND BRAINSTEM CYST AFTER MICROVASCULAR DECOMPRESSION FOR TRIGEMINAL NEURALGIA

OBJECTIVE

Microvascular decompression is commonly performed for medically refractory trigeminal neuralgia. A piece of polytetrafluoroethylene (PTFE) is usually placed between the trigeminal nerve and the blood vessel causing the compression. The procedure is effective and relatively safe, and PTFE is presumed to be inert. Reactions to PTFE are rare.

CLINICAL PRESENTATION

We report a patient who developed progressive neurological symptoms 5 years after microvascular decompression surgery. Imaging showed an enhancing cerebellopontine mass resembling a posterior fossa tumor with a large cyst compressing the brainstem.

INTERVENTION

Craniotomy was performed to decompress the cyst. Biopsy of the enhancing mass showed granulomatous inflammation. The patient underwent a second brainstem decompression surgery with placement of a catheter in the cyst connected to an Ommaya reservoir; she has moderate to severe residual neurological deficits.

CONCLUSION

This may be the first case of a severely disabling, space-occupying cyst resulting from a reaction to intracranial PTFE. Should this exceptionally rare complication be disclosed to patients or is it an idiosyncratic reaction unlikely to occur again?

The management of cervical dystonia

Cervical dystonia (CD), also known as 'spasmodic torticollis', is the most common form of adult-onset focal dystonia. It is a chronic disorder for which there is no curative treatment. Proposed interventions only have a symptomatic effect that is directed at controlling the intensity of the dystonic contractions and their associated symptoms. Both serotypes of botulinum toxin (BtA and BtB) have shown efficacy for the treatment of CD, and they constitute the first-line therapy for CD. BtB constitutes the best medical treatment for secondary failures to BtA. The efficacy of all other proposed medications, including anticholinergics, should be considered unknown due to the lack of good-quality trials. This lack of evidence applies also to all physical rehabilitation treatments. Although the authors have concluded that all surgical procedures for CD should still be considered investigational, the best data supporting benefit of surgery comes from case series of selective peripheral denervation and pallidal deep brain stimulation.

A systematic review on the diagnosis and treatment of primary (idiopathic) dystonia and dystonia plus syndromes: report of an EFNS/MDS-ES Task Force

To review the literature on primary dystonia and dystonia plus and to provide evidence-based recommendations. Primary dystonia and dystonia plus are chronic and often disabling conditions with a widespread spectrum mainly in young people. Computerized MEDLINE and EMBASE literature reviews (1966-1967 February 2005) were conducted. The Cochrane Library was searched for relevant citations. Diagnosis and classification of dystonia are highly relevant for providing appropriate management and prognostic information, and genetic counselling. Expert observation is suggested. DYT-1 gene testing in conjunction with genetic counselling is recommended for patients with primary dystonia with onset before age 30 years and in those with an affected relative with early onset. Positive genetic testing for dystonia (e.g. DYT-1) is not sufficient to make diagnosis of dystonia. Individuals with myoclonus should be tested for the epsilon-sarcoglycan gene (DYT-11). A levodopa trial is warranted in every patient with early onset dystonia without an alternative diagnosis. Brain imaging is not routinely required when there is a confident diagnosis of primary dystonia in adult patients, whereas it is necessary in the paediatric population. Botulinum toxin (BoNT) type A (or type B if there is resistance to type A) can be regarded as first line treatment for primary cranial (excluding oromandibular) or cervical dystonia and can be effective in writing dystonia. Actual evidence is lacking on direct comparison of the clinical efficacy and safety of BoNT-A vs. BoNT-B. Pallidal deep brain stimulation (DBS) is considered a good option, particularly for generalized or cervical dystonia, after medication or BoNT have failed to provide adequate improvement. Selective peripheral denervation is a safe procedure that is indicated exclusively in cervical dystonia. Intrathecal baclofen can be indicated in patients where secondary dystonia is combined with spasticity. The absolute and comparative efficacy and tolerability of drugs in dystonia, including anticholinergic and antidopaminergic drugs, is poorly documented and no evidence-based recommendations can be made to guide prescribing.

Technique of microvascular decompression

Vascular compression of the trigeminal nerve in the cerebellopontine angle is now generally accepted as the primary source or “trigger” causing trigeminal neuralgia. A clear clinicopathological association exists in the neurovascular relationship. In general, pain in the third division of the trigeminal nerve is caused by rostral compression, pain in the second division is caused by medial or more distant compression, and pain in the first division is caused by caudal compression.

This discussion of the surgical technique includes details on patient position, placement of the incision and craniectomy, microsurgical exposure of the supralateral cerebellopontine angle, visualization of the trigeminal nerve and vascular pathological features, microvascular decompression, and wound closure. Nuances of the technique are best learned in the company of a surgeon who has a longer experience with this procedure.

Type 2 diabetes mellitus, etiology and possible treatment: preliminary report

BACKGROUND

Insulin resistance has been proposed as the initial step in the cascade toward type 2 diabetes mellitus. The mechanisms underlying the development of insulin resistance are not fully understood. We hypothesize that neurovascular interactions, in particular arterial elongation, causes compression of the right lateral medulla, triggering a state of autonomic dysfunction including hyperactivity of pancreatic endocrine function, and predisposes to insulin resistance and the development of type 2 diabetes.

METHODS

The clinical and operative findings were reviewed retrospectively in 15 patients with primary diagnoses of various right-sided cranial rhizopathies, but with a common diagnosis of type 2 diabetes mellitus. After microvascular decompression was performed for the primary diagnosis, arterial compression was observed of the lateral medulla and cranial nerve X and treated with microvascular decompression. Known duration of the diabetes ranged from "new" (patient was diagnosed as a result of preoperative blood work) to 16 years (mean 7.3 years). Duration of diabetes diagnosis was unknown in 2 patients. Follow-up was from 3 to 113 months (mean 29.9 months).

RESULTS

Ten of the 15 patients (66%) showed improvement in their blood glucose control; 5 of those 10 (50%) did so with no (4 patients) or less (1 patient) diabetes medication.

CONCLUSIONS

We have shown that arterial compression of the right lateral medulla is consistently present in patients with diabetes mellitus and that microvascular decompression can be performed safely. Further studies are necessary and are under way.

Computed tomographically-controlled injection of botulinum toxin into the longus colli muscle in severe anterocollis

We report on a 44-year-old man who suffered from severe anterocollis. Repeated computed tomographically controlled injections of botulinum toxin into the right longus colli muscle allowed a precise location of the needle and injection of the toxin, leading to clear improvement of symptoms.

Surgical therapy for dystonia

Surgical treatments for dystonia have been available since the early 20th century, but have improved in their efficacy to adversity ratio through a combination of technologic advances and better understanding of the role of the basal ganglia in dystonia. The word "dystonia" describes a phenotype of involuntary movement that may manifest from a variety of conditions. Dystonia may affect only certain regions of the body or may be generalized. It appears to be critical to determine whether the etiology underlying the dystonia is "primary" (ie, occurring from a genetic or idiopathic origin) or "secondary" (ie, occurring as a result of structural, metabolic, or neurodegenerative disorders). Secondary dystonias are far more common than primary dystonias. Primary dystonias respond well to pallidotomy or deep brain stimulation of the internal segment of the globus pallidum, whereas secondary dystonias appear to respond partially at best. Limited historic and current data suggest that the thalamus may be a promising target for the treatment of secondary dystonias, but more careful, prospective, randomized studies are needed. Combinations of bilateral targets are possible with the current technology of DBS, but not widely used due to surgical morbidity and expense. This article reviews the surgical treatment of dystonia from past to present, with a focus on separating the outcomes for primary versus secondary and generalized versus cervical dystonia.

Selective peripheral denervation for the treatment of intractable spasmodic torticollis: experience with 168 patients at the Mayo Clinic

OBJECT

Selective peripheral denervation is currently the primary surgical treatment for intractable cervical dystonia. The authors assessed preoperative factors to determine which, if any, correlated with outcomes in patients with torticollis who had undergone this procedure.

METHODS

The records of 168 consecutive patients who had undergone selective peripheral denervation for cervical dystonia between 1988 and 1996 at the Mayo Clinic were reviewed. There were 89 women (53%) and 79 men (47%) with a mean age of 53.4 years. Selection of muscles for denervation was based on the patient's clinical presentation and electromyography mapping results. The most common torticollis vectors were rotational in 141 patients (84%) and laterocollis in 59 (35%). Seventy patients (42%) presented with combined vectors. The technique used to remedy both conditions involved denervation of the ipsilateral posterior cervical paraspinal and splenius capitis muscles. Denervation of the sternocleidomastoid muscle was performed on the contralateral side for rotational torticollis and on the ipsilateral side for laterocollis. A rigorous physical therapy program followed surgery. At the 3-month postoperative evaluation, 125 patients (77%) of the 162 who were available for follow up had moderate to excellent improvement in their head position, and pain was moderately to markedly improved in 131 patients (81%). The long-term follow up lasted a mean of 3.4 years and was undertaken in 130 patients. The original level of moderate to excellent improvement in head position and pain was retained in at least 71 patients (70%). Outcome was not predicted by preoperative head position, severity of abnormal posture of head, symptom duration, presence of tremor or phasic dystonic movements, or failure to respond to botulinum toxin treatment. Five patients recovered from postoperative complications including one myocardial infarction, one pulmonary embolism, and three respiratory failures. Three patients suffered from persistent C-2 distribution dysesthesias and three from slight shoulder weakness; one had a wound infection, and one died of respiratory arrest.

CONCLUSIONS

Selective peripheral denervation is an effective method of achieving lasting improvement of dystonia in most patients with intractable torticollis.

Selective peripheral denervation for spasmodic torticollis: 13-year experience with 155 patients

OBJECT

Botulinum toxin injections are the best therapeutic option in patients with spasmodic torticollis. Although a small number of patients do not benefit from such therapy, the majority respond well but may develop antibodies to the toxin after repeated applications. In those termed primary nonresponders, no improvement related to botulinum toxin has been shown. In patients in whom no response was shown and those in whom resistance to the therapy developed, selective peripheral denervation is a neurosurgical option.

METHODS

Between June 1988 and August 2001, 155 patients underwent selective peripheral denervation. Surgery was performed at a mean of 8.5 years after the onset of symptoms (range 0.5-37 years). The mean age of the patients at the onset of dystonia was 39.7 years (range 17-77 years). For evaluation of results, patients' responses were assessed. Results were obtained in 140 patients in whom the follow-up period ranged from 3 to 124 months (mean 32.8 months): 18 reported complete relief of their symptoms, 50 significant relief, and 34 moderate relief; 19 noted only minor relief and the remaining 19 no improvement. The results differ substantially when compared with those previously demonstrated in patients who received botulinum toxin injections. Although 80% of the secondary nonresponders were satisfied with the result of surgery, only 62% of the primary nonresponders considered the operation helpful. There were no major side effects. The recurrence rate was 11%.

CONCLUSIONS

The injection of botulinum toxin should be the first-choice treatment. If surgery is required, selective peripheral denervation provides the best results and has the fewest side effects compared with all surgical options.

Cervical dystonia pathophysiology and treatment options

Dystonia is a syndrome of sustained involuntary muscle contractions, frequently causing twisting and repetitive movements or abnormal posturing. Cervical dystonia (CD) is a form of dystonia that involves neck muscles. However, CD is not the only cause of neck rotation. Torticollis may be caused by orthopaedic, musculofibrotic, infectious and other neurological conditions that affect the anatomy of the neck, and structural causes. It is estimated that there are between 60,000 and 90,000 patients with CD in the US. The majority of the patients present with a combination of neck rotation (rotatory torticollis or rotatocollis), flexion (anterocollis), extension (retrocollis), head tilt (laterocollis) or a lateral or sagittal shift. Neck posturing may be either tonic, clonic or tremulous, and may result in permanent and fixed contractures. Sensory tricks ('geste antagonistique') often temporarily ameliorate dystonic movements and postures. Commonly used sensory tricks by patients with CD include touching the chin, back of the head or top of the head. Patients with CD are classified according to aetiology into two groups: primary CD (idiopathic--may be genetic or sporadic) or secondary CD (symptomatic). Patients with primary CD have no evidence by history, physical examination or laboratory studies (except primary dystonia gene) of any secondary cause for the dystonic symptoms. CD is a part of either generalised or focal dystonic syndrome which may have a genetic basis, with an identifiable genetic association. Secondary or symptomatic CD may be caused by central or peripheral trauma, exposure to dopamine receptor antagonists (tardive), neurodegenerative disease, and other conditions associated with abnormal functioning of the basal ganglia. In the majority of patients with CD, the aetiology is not identifiable and the disorder is often classified as primary. Unless the aetiological investigation reveals a specific therapeutic intervention, therapy for CD is symptomatic. It includes supportive therapy and counselling, physical therapy, pharmacotherapy, chemodenervation [botulinum toxin (BTX), phenol, alcohol], and central and peripheral surgical therapy. The most widely used and accepted therapy for CD is local intramuscular injections of BTX-type A. Currently, both BTX type A and type B are commercially available, and type F has undergone testing. Pharmacotherapy, including anticholinergics, dopaminergic depleting and blocking agents, and other muscle relaxants can be used alone or in combination with other therapeutic interventions. Surgery is usually reserved for patients with CD in whom other forms of treatment have failed.

Spontaneous craniocervical osseous fusion resulting from cervical dystonia. Case report

The authors report on a 31-year-old man with spontaneous craniocervical osseous fusion secondary to cervical dystonia (CD). After an 8-year history of severe CD, the patient developed a fixed rotation of his head to the right. Three-dimensional computerized tomography reconstructions revealed rotation and fixation of the occiput and C-1 relative to C-2, which was similar to that seen in atlantoaxial rotatory fixation. There was abnormal ossification of the odontoid facet joints and ligaments. Additional ossification was observed in the cervical soft tissue bridging the lateral mass of C-1 and the occiput. The patient underwent partial myectomy of the dystonic left sternocleidomastoid muscle and selective posterior ramisectomy of the right posterior neck muscles; postoperatively he experienced relief of his neck pain. In patients with CD refractory to conservative treatment, the appropriate timing of surgical treatment is important.

Spasmodic torticollis due to neurovascular compression of the spinal accessory nerve by the anteroinferior cerebellar artery: case report

OBJECTIVE AND IMPORTANCE

Spasmodic torticollis is a neuromuscular disorder characterized by uncontrollable clonic and intermittently tonic spasm of the neck muscles. We report a case of spasmodic torticollis attributable to neurovascular compression of the right XIth cranial nerve by the right anteroinferior cerebellar artery (AICA).

CLINICAL PRESENTATION

A 72-year-old man with a 2-year history of right spasmodic torticollis underwent magnetic resonance imaging, which demonstrated compression of the right XIth cranial nerve by an abnormal descending loop of the right AICA.

INTERVENTION

The patient underwent microvascular decompression surgery. During surgery, it was confirmed that an abnormal loop of the right AICA was compressing the right accessory nerve. Compression was released by the interposition of muscle between the artery and the nerve.

CONCLUSION

The patient's postoperative course was uneventful, and his symptoms were fully relieved at the 2-year follow-up examination. This is the first reported case of spasmodic torticollis attributable to compression by the AICA; usually, the blood vessels involved are the vertebral artery and the posteroinferior cerebellar artery.

Neurovascular compression of the trigeminal and glossopharyngeal nerve: three case reports

Trigeminal neuralgia (TN) is a frequent cause of paroxysmal facial pain and headache in adults. Glossopharyngeal neuralgia (GPN) is less common, but can cause severe episodic pain in the ear and throat. Neurovascular compression of the appropriate cranial nerve as it leaves the brain stem is responsible for the symptoms in many patients, and neurosurgical decompression of the nerve is now a well accepted treatment in adults with both TN and GPN who fail to respond to drug therapy. Neither TN nor GPN are routinely considered in the differential diagnosis when assessing children with paroxysmal facial or head pain, as they are not reported to occur in childhood. Case reports of three children with documented neurovascular compression causing severe neuralgic pain and disability are presented. The fact that these conditions do occur in the paediatric population, albeit rarely, is highlighted, and appropriate investigation and management are discussed.

Cervical Dystonia (Torticollis)

During the initial consultation, the patient is introduced to the five basic treatment options, acknowledging that in most cases, the choice is in the patient's control. The options are 1) supportive/social treatment, 2) physical therapies, 3) oral and intrathecal pharmacotherapy, 4) injection (botulinum toxin type A ) therapy, and 5) surgical therapy. Although a patient may be an obvious candidate for a specific intervention, the patient needs to be aware of the options, including those that he or she chooses not to use. Combination therapies are often appropriate. The option of supportive therapy is applicable in nearly all situations. All patients are encouraged to join a dystonia advocacy association. To accomplish this, literature is made available to them, and the telephone number of the local dystonia chapter is provided. For most patients with focal dystonia or symptoms limited to one region, such as those with cervical dystonia, local injections of botulinum toxin type A are core treatment. For those who cannot be treated effectively with BTX-A, or for those in whom BTX-A has failed, pharmacotherapy is instituted. Pharmacotherapy can often "take the edge off" symptoms that remain after BTX-A therapy. Physical therapies are recommended as complementary treatment for most patients receiving BTX-A in an attempt to extend the benefit from BTX-A. BTX-A may substantially change motor patterns, requiring physical therapies to help the patient relearn normal postures and functional control. In refractory cases when all other measures have failed, peripheral or brain surgery is considered. With our advancing understanding of the genetics of dystonia, it is hoped that specific therapy to either halt the progression of or bring additional relief to dystonic spasms will be available shortly.

Functional outcome and the effect of cranioplasty after retromastoid craniectomy for microvascular decompression

BACKGROUND

While the efficacy of retromastoid craniectomy for microvascular decompression for hyperactive cranial nerve syndromes is well established, there is no real information regarding the functional outcome of these operations. The purpose of this retrospective questionnaire study is to assess functional outcome regarding presence and duration of postoperative headache, incisional pain, and the time to return to normal activity in patients undergoing retromastoid craniectomy for microvascular decompression. The effect of closure with bone chips or cranioplasty in the defect upon these functional outcomes was studied, as was the influence of the particular nerve that was the object of decompression.

METHODS

Four-hundred and ninety-five consecutive patients were contacted and 320 (65%) returned questionnaires with enough information to be suitable for analysis.

RESULTS

The incidence of postoperative headache was initially 60.1%, dropping to 28.8% at 1 month and 16.8% at 6 months. Incisional pain likewise declined with time, noted in 25.8% at 1 month and only 13.1% at 6 months. Use of a cranioplasty made no significant difference in influencing either postoperative headache or incisional pain, nor was the nature of the procedure a significant factor.

CONCLUSION

Twenty-five percent of patients resumed normal activity by 3 weeks, 50% by 1 month, and 90% by 3 months. Overall, 98% of patients responding reported returning to normal activity. Therefore, although there is an incidence of postoperative headache and incisional pain, these decrease with time and do not seem to interfere with the return to normal activity, nor are they affected by placement of a cranioplasty or the nature of the operation.

Understanding and measurement of muscle tone as related to clinical muscle pain

Measurable sources of muscle tension include viscoelastic tone, physiological contracture (neither of which involve motor unit action potentials), voluntary contraction, and muscle spasm (which we define as involuntary muscle contraction). The latter two depend on motor unit action potentials to generate the tension. Total muscle tension is most accurately measured as stiffness. Thixotropy of muscle is an ubiquitous and functionally important phenomenon that is not commonly recognized. A clinical pain condition associated with increased muscle tension is tension-type headache, which is largely muscular in origin; it is often caused by myofascial trigger points, but not by a pain-spasm-pain cycle, which is a physiologically and clinically untenable concept. Clinical conditions associated with painful muscle spasm include spasmodic torticollis, trismus, unnecessary muscle tension, nocturnal leg cramps, and stiff-man syndrome.

Symptomatic and functional outcome of surgical treatment of cervical dystonia

OBJECTIVES

Previous studies of surgical treatment for cervical dystonia have reported highly variable rates of postoperative symptomatic benefit and morbidity. Little is known about functional improvement and long term results. This study evaluates the symptomatic and functional outcome of surgical treatment of cervical dystonia in a consecutive series of 46 patients.

METHODS

The most affected muscles were selected for denervation after clinical examination and confirmation by four channel EMG studies. Surgical treatment, aiming at selective elimination of pathological activity while preserving normal motor function and avoiding side effects, was achieved by using a broad scope of techniques including intradural denervation, extradural denervation, and myotomy. Rather than carrying out standard operations, the treatment was tailored to the needs of the patient according to the individual pattern of dystonic activity. Long term benefit was assessed with a global outcome score, and a modified Toronto western spasmodic torticollis rating scale (TWSTRS) in those 34 patients who were available for a recent follow up evaluation.

RESULTS

The 46 patients underwent a total of 70 procedures with intradural approaches in 33 instances, extradural approaches in 21, and muscle sections (singly or combined) in 22 instances. Transient mild postoperative side effects occurred in 10% of the procedures. The mean duration of long term follow up was 6.5 years. The global outcome was rated as excellent in nine patients (21%), as marked in 12 (27%), as moderate in nine (21%), as mild in nine (21%), and as no improvement in five (11%). A persistent side effect consisting of mild difficulty with balance was noted in one case. There were highly significant changes of the preoperative and postoperative mean values for almost all TWSTRS subscores for severity of cervical dystonia, functional disability, and pain. Patients with excellent outcome underwent a higher number of surgical procedures on average than those patients who achieved no benefit.

CONCLUSIONS

Surgical treatment tailored to the specific pattern of dystonic activity in the individual patient is a valuable alternative in the long term management of cervical dystonia.

Cervical dystonia associated with tumors of the posterior fossa

Cervical dystonia was associated with posterior fossa tumors in three patients. The onset of dystonia paralleled the appearance of other focal neurologic signs. All patients had extraaxial tumors located in the cerebellopontine angle that were removed via suboccipital approaches. The tumors were identified as schwannomas arising from the glossopharyngeal nerve and from the vagus/accessory nerves; and a meningioma. Postoperatively, the cervical dystonia improved markedly during a period of 8 years in one patient, and it remitted completely within 1 year in another patient. In the third patient, cervical dystonia persisted. The combination of the clinical findings and the temporal relationship of their appearance suggest a causal association between the posterior fossa tumors and cervical dystonia in three cases. Possible pathogenic mechanisms are reviewed.