Outcomes after spinal stenosis surgery by type of surgery in adults aged 60 years and older.

AIMS OF THE STUDY: Mobility disability due to spinal stenosis is common in the senior population and often surgery is warranted for patients with severe symptoms and neurological dysfunction. However, although current clinical guidelines recommend stabilisation surgery in addition to decompression in patients with spinal stenosis and instability due to degenerative spondylolisthesis, the relationship between outcomes and the specific type of surgery have not been well studied. We therefore assessed the postoperative recovery timeline for 12 months and compared patient-reported outcomes dependent on the extent of decompression and additional stabilisation among seniors undergoing spinal stenosis surgery. METHODS: We investigated 457 patients (mean age 76.0 ± 10.7 years, 58% women) from a consecutive cohort prior to spinal stenosis surgery. Follow-up was at 3 or 6months and at 12 months postoperatively. At each visit, pain, neurological dysfunction and disability were assessed using the North American Spine Society questionnaire. Repeated-measures analysis compared outcomes by type of surgery adjusting for baseline symptoms, gender, age, number of comorbidities, centre and year of surgery. RESULTS: Most improvement occurred within the first 3 to 6 months with little or no further improvement at 12 months. Over 12 months and in adjusted models, patients receiving one-segment versus multi-segment decompression experienced significantly greater reduction of pain (−49.2% vs −41.9%, p = 0.013) and neurological dysfunction (−37.1% vs −25.9%, p <0.0001), but only borderline greater reduction of disability (−32.7% vs −28.2%, p = 0.051). Moreover, reduction in pain and neurological function did not differ with or without additional stabilisation and extend of decompression. However, patients who received one-segment (−28.9%) or multi-segment (−28.3%) stabilisation experienced significantly less reduction in disability after surgery compared with those who were not stabilised (−34.1%, p <0.043). CONCLUSIONS: Among senior patients undergoing spinal stenosis surgery, recovery was largely complete by 3 to 6 months after surgery and differed little by type of surgery independently of symptoms prior to surgery and other covariates. However we could document a trend toward more improvement in particularly neurological dysfunction and disability with less invasive surgery.

What is the treatment effect of surgery compared with nonoperative treatment in patients with lumbar spinal stenosis at 1-year follow-up?

Objective: The aim of this study was to obtain an unbiased causal treatment estimate of the between-group difference of surgery versus nonoperative treatment with respect to outcomes on quality of life, pain, and disability in patients with degenerative lumbar spinal stenosis (DLSS) 12 months after baseline. Methods: The authors included DLSS patients from a large prospective multicenter observational cohort study. Propensity score matching was used, including 15 demographic, clinical, and MRI variables. Linear and logistic mixed-effects regression models were applied to quantify the between-group treatment effect. Unmeasured confounding was addressed in a sensitivity analysis, assessing the robustness of the results. Results: A total of 408 patients were included in this study, 222 patients after matching, with 111 in each treatment group. Patients with nonoperative treatment had lower quality of life at the 12-month follow-up (−6.21 points, 95% CI −9.93 to −2.49) as well as lower chances of reaching a minimal clinically important difference in Spinal Stenosis Measure (SSM) symptoms (OR 0.26, 95% CI 0.13 to 0.53) and SSM function (OR 0.26, 95% CI 0.14 to 0.49), than patients undergoing surgery. These results were very robust in case of unmeasured confounding. The surgical complication rate was low; 5 (4.5%) patients experienced a durotomy during intervention, and 5 (4.5%) patients underwent re-decompression. Conclusions: The authors used propensity score matching to assess the difference in treatment efficacy of surgery compared with nonoperative treatment in elderly patients with DLSS. This study delivers strong evidence that surgical treatment is superior to nonoperative treatment. It helps in clinical decision-making, especially when patients suffer for a long time, sometimes over many years, hoping for a spontaneous improvement of their symptoms. In light of these new results, the number of years with disability can hopefully be reduced by providing adequate treatment at the right time for this ever-growing elderly and frail population. Abbreviations: DLSS = degenerative lumbar spinal stenosis; HADS = Hospital Anxiety and Depression Scale; ITT = intention-to-treat; LSOS = Lumbar Stenosis Outcome Study; MCID = minimal clinically important difference; RCT = randomized controlled trial; SMD = standardized mean difference; SSM = Spinal Stenosis Measure.

Cisternal segments of the glossopharyngeal, vagus, and accessory nerves: detailed magnetic resonance imaging-demonstrated anatomy and neurovascular relationships.

OBJECT: The aim of this study was to determine whether high-resolution MR imaging is suitable for identifying and differentiating among the nerve root bundles of the glossopharyngeal (cranial nerve [CN] IX), vagus (CN X), and accessory nerves (CN XI) as well as any adjacent vessels. METHODS: Twenty-five patients (50 sides) underwent MR imaging using the 3D constructive interference in steady-state (CISS) sequence, as well as noncontrast and contrast-enhanced 3D time-of-flight (TOF) MR angiography. Two individuals scored these studies by consensus to determine how well these sequences displayed the neurovascular contacts and nerve root bundles of CNs IX and X and the cranial and spinal roots of CN XI. Landmarks useful for identifying each lower CN were specifically sought. RESULTS: The 3D CISS sequence successfully depicted CNs IX and X in 100% of the sides. Nerve root bundles of the cranial segment of CN XI were identified in 88% of the sides and those of the spinal segment of CN XI were noted in 93% of the sides. Landmarks useful in identifying the lower CNs included the vagal trigone, the choroid plexus of the lateral recess, the glossopharyngeal and vagal meatus, the inferior petrosal sinus, and the vertebral artery. The combined use of 3D CISS and 3D TOF sequences demonstrated neurovascular contacts at the nerve root entry or exit zones in 19% of all nerves visualized. CONCLUSIONS: The combined use of 3D CISS MR imaging and 3D TOF MR angiography (with or without contrast) successfully displays the detailed anatomy of the lower CNs and adjacent structures in vivo. These imaging sequences have the potential to aid the preoperative diagnosis of and the presurgical planning for pathology in this anatomical area.

Trigeminal ganglion and its divisions: detailed anatomic MR imaging with contrast-enhanced 3D constructive interference in the steady state sequences.

BACKGROUND AND PURPOSE: Visualization of the trigeminal system is important for imaging diagnosis but technically challenging. We assessed how well the trigeminal ganglion, its rootlets, and its branches (V1, V2, and V3) are depicted on three high-resolution pulse sequences. METHODS: Twenty-two patients (44 sides) underwent nonenhanced 3D constructive interference in the steady state (CISS) MR imaging. Two of these patients and another 20 (44 sides) also underwent contrast-enhanced 3D CISS and contrast-enhanced 3D time-of-flight (TOF) MR angiographic (MRA) imaging. Appearances of the ganglion, sinus ganglii, ganglion lip, and sensory and motor rootlets in the Meckel cave were assessed. RESULTS: The trigeminal ganglion was shown on enhanced 3D CISS images in all cases, on nonenhanced 3D CISS images in 77.3%, and on enhanced 3D TOF MRA images in 92.9%. Sinus ganglia and lips were demonstrated on 98% of enhanced 3D CISS images. Sensory rootlets were depicted with all 3D CISS sequences but no 3D TOF sequences. V1, V2, and V3 were displayed with all enhanced 3D TOF MRA sequences, 79.5-100% of enhanced 3D CISS sequences, and 0-50% of nonenhanced 3D CISS sequences. CONCLUSION: The enhanced 3D CISS sequence was best for displaying the trigeminal ganglion, sinus ganglii, and sinus lips, whereas the enhanced 3D TOF sequence best displayed the emerging V1, V2, and V3 roots. The enhanced 3D CISS sequence was most useful. Complete MR imaging evaluation of the trigeminal ganglion and roots is best performed by using enhanced 3D CISS and enhanced 3D TOF MRA sequences.

Detailed anatomy of the motor and sensory roots of the trigeminal nerve and their neurovascular relationships: a magnetic resonance imaging study.

OBJECT: The trigeminal nerve conducts both sensory and motor impulses. Separate superior and inferior motor roots typically emerge from the pons just anterosuperomedial to the entry point of the sensory root, but to date these two motor roots have not been adequately displayed on magnetic resonance (MR) images. The specific aims of this study, therefore, were to identify the superior and inferior motor roots, to describe their exact relationship to the sensory root, and to assess the neurovascular relationships among all three roots of the trigeminal nerve. METHODS: Thirty-three patients and seven cadaveric specimens (80 sides) were studied using three-dimensional (3D) Fourier transform constructive interference in steady-state (CISS) imaging. The 33 patients were also studied by obtaining complementary time-of-flight (TOF) MR angiography sequences with and without contrast enhancement. At least one motor root was identified in all sides examined: in 51.2% of the sides a single motor root, in 37.5% two motor roots, and in 11.2% three motor roots. The superior cerebellar artery (SCA) and the anterior inferior cerebellar artery (AICA) contacted the sensory root in 45.5% of patients and 42.9% of specimens. The SCA often contacted the superior motor root (48.5% of patients and 50% of specimens) and less frequently the inferior motor root (26.5% of patients and 20% of specimens). CONCLUSIONS: Three-dimensional CISS and complementary 3D TOF MR angiography sequences reliably display sensory, superior motor, and inferior motor roots of the trigeminal nerve and their relationships to the SCA and AICA.

Processing of temporal duration information in working memory after frontodorsal tumour excisions.

This study aimed to test the hypothesis that impairments of temporal duration processing after frontal lobe lesions reflect deficits in executive monitoring functions rather than a domain-specific deficit in the maintenance of duration information in working memory. Patients with frontodorsal lesions, clinical controls with post-central lesions, and healthy controls performed recognition and classification tasks, which should allow for testing maintenance and monitoring functions, respectively. Results showed mild non-selective impairments of the frontal patients on both temporal and spatial recognition tasks, but a marked selective degradation on temporal classification while performance on spatial classification was unimpaired. This suggests that maintenance of duration information in working memory after frontal lesions is basically preserved but that, depending on executive task characteristics, there is a specific deficit in the strategic organization of this type of information.

Detailed anatomy of the intracranial segment of the hypoglossal nerve: neurovascular relationships and landmarks on magnetic resonance imaging sequences.

OBJECT: The thin hypoglossal nerve can be very difficult to distinguish on magnetic resonance (MR) images. The authors used a combination of sequences to increase the reliability of MR imaging in its demonstration of the 12th cranial nerve as well as to assess the course of the nerve, display its relationships to adjacent vessels, and provide landmarks for evaluating the nerve in daily practice. METHODS: The study group consisted of 34 volunteers (68 nerves) in whom a three-dimensional (3D) Fourier-transformation constructive interference in steady-state (CISS) sequence and a 3D T1-weighted contrast-enhanced magnetization-prepared rapid-acquisition gradient-echo (MPRAGE) sequence were applied. Two trained neuroradiologists collaboratively identified the hypoglossal trigone, preolivary sulcus, 12th cranial nerve, posterior inferior cerebellar artery, vertebral artery, 12th nerve root sleeve, and the hypoglossal canal on each side. The 3D CISS sequence successfully demonstrated the hypoglossal trigone (100% of images), 12th nerve root bundles (100% of images), and 12th nerve sleeves (88.2% of images). The canalicular segment was exhibited with the aid of plain 3D CISS sequences in 74% of images and by using contrast-enhanced 3D CISS sequences and contrast-enhanced MPRAGE sequences in 100% of images. The landmarks that proved useful to identify the cisternal segment of the 12th cranial nerve included the hypoglossal trigone, preolivary sulcus, and 12th nerve root sleeve. Neurovascular contact was identified in 61% of root bundles. The roots were distorted in 44% of these contacts. CONCLUSIONS: The contrast-enhanced 3D CISS sequence consistently displayed the cisternal segment as well as the canalicular segments of the hypoglossal nerve and is, therefore, the best sequence to visualize the complete cranial course of this nerve. Landmarks such as the 12th nerve sleeves can assist in the identification of this nerve.

MR anatomy of the proximal cisternal segment of the trochlear nerve: neurovascular relationships and landmarks.

PURPOSE: To assess the anatomic features and vascular relationships of the proximal portion of the cisternal segment of the trochlear nerve. MATERIALS AND METHODS: In 30 subjects (60 nerves) and in one patient with right superior oblique myokymia (SOM), the anatomy of the trochlear nerve was depicted with three-dimensional (3D) Fourier transformation constructive interference in steady state (CISS) magnetic resonance (MR) imaging, whereas the adjacent vessels were detected with 3D time-of-flight (TOF) MR imaging before and after gadopentetate dimeglumine administration. The images were evaluated with respect to the identification of the trochlear nerve, the distance between the point of exit (PE) and the midline, the visualized length, the vascular relationships, and the distance between the PE and the point of neurovascular contact. RESULTS: 3D CISS MR imaging depicted the proximal cisternal segment of the trochlear nerve in the transverse, sagittal, and coronal planes in 57 (95%), 51 (85%), and 48 (80%) of 60 nerves, respectively. The distance from the midline to the PE was 3-9 mm, and the maximum visualized length of the trochlear nerve was 1-14 mm. An arterial-trochlear neurovascular contact was seen at the root exit zone (REZ) in eight (14%) nerves and at a mean distance of 3.4 mm distal to the PE in 29 nerves (51%). The patient with SOM had arterial-trochlear neurovascular contact at the REZ. CONCLUSION: Use of 3D CISS sequences and 3D TOF sequences with or without gadopentetate dimeglumine enables accurate identification of the proximal cisternal segment of the trochlear nerve and its neurovascular relationships.

Superior oblique myokymia: magnetic resonance imaging support for the neurovascular compression hypothesis.

Superior oblique myokymia is a rare movement disorder thought to be caused by vascular compression of the trochlear nerve. Direct display of such neurovascular compression by magnetic resonance imaging has been lacking. The goal of this study was to assess the presence of neurovascular contacts in patients with superior oblique myokymia, using a specific magnetic resonance imaging protocol. A total of 6 patients suffering from right superior oblique myokymia underwent detailed neuro-ophthalmological examination, which showed tonic or phasic eye movement. All patients underwent magnetic resonance imaging, using a magnetic resonance imaging Fourier transform constructive interference in steady-state sequence in combination with magnetic resonance imaging time of flight magnetic resonance arteriography both before and after the administration of Gd-DTPA. With this protocol, the trochlear nerve could be visualized on 11 of 12 sides (92%). Arterial contact was detected at the root exit zone of the symptomatic right trochlear nerve in all 6 patients (100%). No arterial contact was identified at the root exit zone of the asymptomatic left trochlear nerve in any of the 5 left nerves visualized. In conclusion, superior oblique myokymia can result from neurovascular contact at the root exit zone of trochlear nerve, and therefore should be considered among the neurovascular compression syndromes.