Table 1 A list of large descriptive case series of KD in the literature (non-exhaustive list)
Author | Aim | Methodology, level of evidence | Population | evaluation parameters | Most significant results |
|---|---|---|---|---|---|
Dejager et al., 2002 [22] | Description of endocrine and metabolic changes | Monocentric cohort study Level of evidence: IV | 22 KD | Gynecomastia, blood hormonal, lipid and glucose assessment | Gynecomastia in 73% of cases, infertility or decrease of testicular volume in 60%, elevation of total cholesterol, LDL-C and triglycerides (54, 40 and 48%, respectively). |
Sperfeld et al., 2005 [23] | Evaluation of the incidence of laryngospasm | Monocentric cohort study Level of evidence: IV | 49 KD | Symptom questionnaire, respiratory tests | 47% of the KD patients experienced laryngospasm. |
Atsuta et al., 2006 [24] | Description of the natural history of KD | Multicentre cohort study Level of evidence: IV | 223 KD | Clinical and biological parameters, Rankin score | Inverse correlation between the number of CAG repeats and the age of onset of symptoms |
Chahin et al., 2008 [25] | Evaluation of functional decline and prognosis | Single centre case-control study Level of evidence: III | 39 KD 70 Controls | 10-year survival rate and functional status (ALSFRS-R) at last follow-up | Survival rate of KD was not significantly altered compared with controls (82% vs 95%, p = 0.053). The functional status was relatively preserved. Patients are mostly limited for climbing the stairs. Bulbar symptoms in all patients but no need for gastrostomy. Non-invasive ventilation was needed in one single patient. |
Rhodes et al., 2009 [26] | Description of the natural history of KD | Single centre cohort study, patients participating in the Dudasteride therapeutic trial. Level of evidence: IV | 57 KD | Neurophysiological, biological, neuropsychological and quality of life parameters | Long diagnostic delay (5 years). Correlation between androgen levels and muscle strength. |
Soukup et al., 2009 [27] | Evaluation of cognition changes in KD | Monocentric case-control study Level of evidence: III | 20 KD 20 Controls | Neuropsychological assessment evaluating executive functions, memory, attention | Existence of a subclinical impairment of frontal and temporal functions |
Hashizume [28] | Characterisation of the natural history of KD | Monocentric cohort study Level of evidence: IV | 34 KD | Quantitative outcome measures including functional and blood parameters | Disease progression is not affected by CAG repeat length Objective motor functional tests such as the 6-min walk test and grip power or serum creatinine levels are more sensitive at an early stage than by the functional rating scales |
Araki et al., 2014 [29] | Evaluation of ECG abnormalities | Monocentric cohort study Level of evidence: IV | 144 KD | ECG parameters | ECG abnormalities in 49% of cases, mainly consisting in ST segment anomalies in V1-V3 (19%) and V5-V6 (18%). Brugada syndrome (12%) with two cases of sudden death |
Querin et al., 2015 [30] | Characterisation of the extraneurological profile of KD | Multicentre cohort study Level of evidence: IV | 73 KD | Biology, androgen sensitivity index, genito-urinary symptoms, dual-energy X-ray absorptiometry, muscle biopsy | Androgen insensitivity. Increased prevalence of genito-urinary symptoms and diminution of bone mass. |
Bertolin et al., 2016 [31] | Genotype-phenotype associations | Multicentre cohort study Level of evidence: IV | 159 KD | Correlation between the number of CAG repeats and motor function | No genotype/phenotype correlations |
Nordenvall et al., 2016 [32] | Establishing the incidence of hypospadias | Data analysis from a national KD registry Level of evidence: IV | 4 KD | Association between hypospadia and KD | Hypospadia in KD may be underestimated |
Francini-Pesenti, 2018 [33] | Evaluating the prevalence of metabolic syndrome | Monocentric cohort study Level of evidence: IV | 47 KD | Metabolic syndrome Insuline resistance Non-alcoholic liver disease | High prevalence of insulin resistance, metabolic syndrome and non-alcoholic liver disease and NAFLD in SBMA patients |
Rosenbohm et al., 2018 [34] | Evaluating the prevalence of metabolic changes | Monocentric cohort study Level of evidence: IV | 80 KD | Panel of 28 laboratory parameters | Diabetes, hyperlipidemia and androgen insensitivity |
Marcato et al., 2018 [35] | Establishing the prevalence of cognitive changes | Monocentric cohort study Level of evidence: IV | 64 KD | Battery of neuropsychological test | Absence of neuropsychological abnormalities |
Spinelli et al., 2019 [36] | Characterising cerebral radiological alterations | Monocentric case-control study. Level of evidence: III | 25 KD 24 Healthy 25 ALS 35 Lower motor neuron-predominant conditions | MRI parameters: cortical thickness and diffusion tensor imaging (DTI) | Absence of abnormalities of the cerebral gray and white matters in KD patients. |