Gait assessment in general practice.

BACKGROUND: Patients with a variety of neuromuscular pathologies may present with gait abnormalities. Accurate assessment of each pattern, coupled with appropriate investigations, facilitates diagnostic accuracy followed by treatment or referral, as required. OBJECTIVE: This review outlines the relevant history and examination areas to assess when interpreting gait abnormalities, together with common gait patterns and their aetiologies. DISCUSSION: A range of factors should be evaluated, including posture, walking aids and footwear. The gait cycle can be broadly divided into the stance and swing phases, and additional features are assessed to identify specific patterns and generate a provisional diagnosis. Gait examination, from the time the patient is called from the waiting room, will help the clinician focus on the relevant systems to examine, investigate and treat.

Long-term health outcomes in survivors after chronic subdural haematoma.

Chronic subdural haematoma (CSDH) is the most common neurosurgical presentation among the elderly. Although initially considered a non-threatening event, recent studies have highlighted poor long-term survival post-CSDH. Currently, there is a paucity of information regarding long-term health outcome in survivors after CSDH post-intervention. The objective of this research was to assess long-term functional, cognitive, and mental health outcome after CSDH. CSDH patients were administered a telephone-based assessment including a Demographic Questionnaire, Functional Activities Questionnaire (FAQ), Cognitive Telephone Screening Instrument (COGTEL), Mental Health Continuum-Short Form (MHC-SF), and the Geriatric Depression Scale (GDS). Results were obtained in n = 51 patients. CSDH patients were assessed at 5.5 + 2.1 years after CSDH and results were compared to age/gender matched controls (n = 52). Comorbidities were significantly greater in CSDH patients at the time of assessment (χ2 = 35.47, P < .01). CSDH patients demonstrated a significant reduction in functional independence (FAQ, P < .001) and Verbal Short-Term Memory (COGTEL, P = .048). Potential negative trends were observed for Verbal Long-Term Memory (P = .06) and Inductive Reasoning (P = .07). CSDH patients also demonstrated significantly poorer emotional, psychological and social well-being (MHC-SF: Emotional, P = .003; Psychological, P = .001; and Social, P < .001), with increased depressive symptomatology (GDS, P < .001). In addition to known decreased long-term survival, CSDH survivors demonstrated poorer long-term functional, cognitive and mental health outcomes than controls. Pre-existent comorbidities were also more prevalent. CSDH is therefore a sentinel health event: survivors represent a vulnerable group who require long-term, comprehensive, person-centred care. This is the first study of long term CSDH health outcomes.

Membrane Surface Area to Volume Ratio in Chronic Subdural Hematomas: Critical Size and Potential Postoperative Target.

BACKGROUND: It is unknown why some chronic subdural hematomas (CSDHs) grow and require surgery, whereas others spontaneously resolve. Although a relatively small CSDH volume (V) reduction may induce resolution, V percent reduction is often unreliable in predicting resolution. Although CSDHs evolve distinctive inner neomembranes and outer neomembranes (OMs), the OM likely dominates the dynamic growth-resorption equilibrium. If other factors remain constant, one previous hypothesis is that resorption could fail as the surface area (SA) to V ratio decreases when CSDHs exceed a critical size. We aimed to identify a critical size and an ideal target, which implies resolution without recurrence. METHODS: Three-dimensional computed tomography CSDH SA to V ratios were obtained using computer software to compare CSDH SA to V between cases requiring surgery (surgical) and cases managed conservatively with spontaneous resolution (nonsurgical). RESULTS: Data were obtained in 45 patients (surgical: n = 28; nonsurgical: n = 17). CSDH risk factors did not significantly differ between surgical and nonsurgical cases. Surgical V was 2.5× the nonsurgical V (119.9 ± 33.1 mL vs. 48.4 ± 27.4 mL, respectively; P < 0.0001). Surgical total SA was 1.4× nonsurgical SA (256.63 ± 70.65 cm2 vs. 187.67 ± 77.72 cm2, respectively; P = 0.004). Surgical total SA to V ratio was approximately one half that of nonsurgical SA to V ratio (2.14 ± 0.90 mL-1 vs. 3.88±1.22 mL-1, respectively; P < 0.0001). Surgical OM SA (SAOM) was 120.63 ± 52 cm2, and nonsurgical SAOM was 94.10 ± 41 cm2 (P < 0.0001). Nonsurgical SAOM to V ratio was 1.94 mL-1, whereas surgical SAOM to V ratio was 1.005 mL-1 (i.e., surgical SAOM ≈ V). CONCLUSIONS: Because surgical total SA to V ratio was ≈2:1, one neomembrane may indeed dominate the dynamic growth-resorption equilibrium. CSDH critical size therefore appears to be when SAOM ≈ V, which is intuitive. Practically, subtotal CSDH evacuation which approximately doubles total SA to V ratio or SAOM to V ratio implies CSDH resolution without recurrence. This could guide subdural drain removal timing, discharge, or transfer. Prospective validation studies are required.

Mathematical formulae to estimate chronic subdural haematoma volume. Flawed assumption regarding ellipsoid morphology.

Mathematical formulae are commonly used to estimate intra-cranial haematoma volume. Such formulae tacitly assume an ellipsoid geometrical morphology. Recently, the 'XYZ/2' formula has been validated and recommended for chronic subdural haematoma (CSDH) volumetric estimation. We aimed to assess the precision and accuracy of mathematical formulae specifically in estimating CSDH volume, and to determine typical CSDH 3-D morphology. Three extant formulae ('XYZ/2', 'π/6·XYZ' and '2/3S·h') were compared against computer-assisted 3D volumetric analysis as Gold standard in CTs where CSDH sufficiently contrasted with brain. Scatter-plots (n=45) indicated that, in contrast to prior reports, all formulae most commonly over-estimated CSDH volume against 3-D Gold standard ('2/3S·h': 44.4%, 'XYZ/2': 48.84% and 'π/6·XYZ': 55.6%). With all formulae, imprecision increased with increased CSDH volume: in particular, with clinically-relevant CSDH volumes (i.e. >50ml). Deviations >10% of equivalence were observed in 60% of estimates for 2/3S·h, 77.8% for 'XYZ/2' and 84.4% for 'π/6·XYZ'. The maximum error for 'XYZ/2' was 142.3% of a clinically-relevant volume. Three-D simulations revealed that only 4/45 (9%) CSDH remotely conformed to ellipsoid geometrical morphology. Most (41/45, 91%) demonstrated highly irregular morphology neither recognisable as ellipsoid, nor as any other regular/non-regular geometric solid. CONCLUSIONS: Mathematical formulae, including 'XYZ/2', most commonly proved inaccurate and imprecise when applied to CSDH. In contrast to prior studies, all most commonly over-estimated CSDH volume. Imprecision increased with CSDH volume, and was maximal with clinically-relevant CSDH volumes. Errors most commonly related to a flawed assumption regarding ellipsoid 3-D CSDH morphology. The validity of mean comparisons, or correlation analyses, used in prior studies is questioned.

Long-term survival after chronic subdural haematoma.

Outcome after chronic subdural haematoma (CSDH) is invariably assumed favourable: however, little data regarding long term survival (LTS) exists. One study reported excess mortality restricted to year 1, but with expected actuarial rates thereafter. We aimed to determine LTS after CSDH in a retrospective analysis relative to actuarial data from age-matched controls. Data was obtained in n=155, (M:F 97:58, 69.3±2.3years). Follow-up maxima was 14.19years (mean: 4.02±3.07years, median: 5.2years). Mortality in-hospital, at 6months, 1year, 2years and 5years was n=13 (8.39%), n=22 (14.19%), n=31 (20.35%), n=42 (27.1%) and n=54 (34.84%). LTS was significantly worse than controls (5.29±0.59years vs. 17.74±1.8years, hazard ratio [HR]: 3.52, P<0.0001). Death most frequently related to pneumonia/sepsis and ischemic heart disease (IHD). Median modified Rankin score (mRS) in those discharged home (n=94, 60.65%) was 2 [IQR: 1-3]. Discharge mRS in those who died at 6months, 1year, 2years and 5years was 5 [IQR: 3-6], 5 [IQR: 4-6], 3 [IQR: 1-3], 4 [IQR: 2-5]. Discharge mRS was significantly worse with year 1 mortality (P=0.014). LTS related to discharge mRS (HR: 37.006, P<0.001), post-operative motor-score (HR: 0.581, P=0.0026), IHD (HR: 5.186, P=0.005), warfarin-use (HR: 5.93, P=0.036) and dementia (HR: 5.39, P=0.031). No long term recurrences (LTR) were recorded. Although most were discharged home with mRS=2, LTS was markedly less than previously reported: peers lived 12.4years longer. Although greater in year 1, excess mortality was not restricted to year 1, but continued throughout prolonged follow-up. LTS related to discharge disability and dependence, and co-morbid risk factors for cerebral atrophy. No LTR suggests that, once ultimately closed, the 'subdural space' remains closed. CSDH patients represent a vulnerable group who require continued long-term medical surveillance.

Risk factors for chronic subdural haematoma formation do not account for the established male bias.

OBJECTIVE: The 'subdural space' is an artefact of inner dural border layer disruption: it is not anatomical but always pathological. A male bias has long been accepted for chronic subdural haematomas (CSDH), and increased male frequencies of trauma and/or alcohol abuse are often cited as likely explanations: however, no study has validated this. We investigated to see which risk factors accounted for the male bias with CSDH. METHODS: Retrospective review of prospectively collected data. RESULTS: A male bias (M:F 97:58) for CSDH was confirmed in n=155 patients. The largest risk factor for CSDH was cerebral atrophy (M:F 94% vs. 91%): whilst a male bias prevailed in mild-moderate cases (M:F 58% vs. 41%), a female bias prevailed for severe atrophy (F:M 50% vs. 36%) (χ(2)=3.88, P=0.14). Risk factors for atrophy also demonstrated a female bias, some approached statistical significance: atrial fibrillation (P=0.05), stroke/TIA (P=0.06) and diabetes mellitus (P=0.07). There was also a trend for older age in females (F:M 72±13 years vs. 68±15 years, P=0.09). The third largest risk factor, after atrophy and trauma (i.e. anti-coagulant and anti-platelet use) was statistically significantly biased towards females (F:M 50% vs. 33%, P=0.04). No risk factor accounted for the established male bias with CSDH. In particular, a history of trauma (head injury or fall [M:F 50% vs. 57%, P=0.37]), and alcohol abuse (M:F 17% vs. 16%, P=0.89) was remarkably similar between genders. CONCLUSIONS: No recognised risk factor for CSDH formation accounted for the established male bias: risk factor trends generally favoured females. In particular, and in contrast to popular belief, a male CSDH bias did not relate to increased male frequencies of trauma and/or alcohol abuse.