1 Epidemiological Characteristics of Neurological Diseases

1.1 Prevalence of Neurological Diseases

Prevalence (per 1,000) of neurological disorders, by cause, WHO region and mortality stratum, projections for 2005, 2015, and 2030
	2005		2015		2030
Population	6,441,919,466	Number per 1,000	7,105,297,899	Number per 1,000	7,917,115,397	Number per 1,000
Epilepsy	39,891,898	6.19	44,568,780	6.27	50,503,933	6.38
Alzheimer’s disease	24,446,651	3.79	31,318,923	4.41	44,016,718	5.56
Parkinson’s disease	5,223,897	0.81	5,967,673	0.84	7,236,712	0.91
Multiple sclerosis	2,492,385	0.39	2,823,092	0.40	3,279,190	0.41
Migraine	326,196,121	50.64	364,432,879	51.30	412,894,420	52.15
Cerebrovascular disease	61,537,499	9.55	67,212,050	0.46	76,826,240	9.70
Neuroinfection	18,169,479	2.82	15,714,399	2.21	13,290,180	1.68
Nutritional/neuropathies	352,494,535	54.72	321,738,424	45.29	285,369,403	36.04
Neurological injuries	170,382,211	26.45	197,627,526	27.82	242,728,912	30.60
Source: Neurological disorders: public health challenges, WHO 2006.

1.2 Epidemiology of Worldwide Neurological Disorders

In order to improve the understanding of the global burden of neurologic conditions, the Public Health Agency of Canada launched the National Population Health Study of Neurological Conditions in 2009. One of its many aims was to examine the epidemiology, including the incidence and prevalence, of 15 common neurologic conditions. This effort involved the review of 65,529 abstracts and 4,650 full-text articles, with 1,242 research studies. In the following tables, the overall worldwide pooled prevalence or incidence data from the systemic reviews of neurologic conditions are presented. The table shows differences that exist. For example, in the Canadian systematic review of the epidemiology of epilepsy, the incidence was highest in Africa at 215.00 per 100,000 person-years, followed by South America at 162.45 per 100,000 person-years. The incidence of epilepsy in North America was 23.29 per 100,000 person-years and it was 42.63 per 100,000 person-years in Europe. These differences in incidence between continents are most likely attributable to the geographic differences in risk factors for epilepsy such as the high prevalence of central nervous system (CNS) infections (i.e., neurocysticercosis) in many developing countries compared to the developed countries. For many conditions, data on the prevalence or incidence of neurologic conditions in Africa and South America were scarce or unavailable, limiting the possibility of drawing firm conclusions in these areas.

Neurological condition	Overall pooled worldwide prevalence or incidence	Region-specific prevalence or incidence
Dementia	Prevalence (community-based, age 65+)	Prevalence (community-based, age 65+)
	4,628 per 100,000 persons	Asia 4,038 per 100,000 persons
	Incidence (community-based, 65+)	Europe 6,758 per 100,000 persons
	4,169 per 100,000 persons	North America 5,097 per 100,000 persons
		South America 3,668 per 100,000 persons
		Incidence (community-based, age 65+)
		Africa 1,350 per 100,000 persons
		Asia 870 per 100,000 persons
		Australia 1,289 per 100,000 persons
		Europe 2,317 per 100,000 persons
		North America 5,830 per 100,000 persons
Tourette syndrome	Prevalence (in children)	Region specific analysis not performed
	770 per 100,000 persons
Epilepsy	Prevalence (active epilepsy)	Prevalence (community-based, age 65+)
	596 per 100,000 persons	Africa 863 per 100,000 persons
	Incidence (active epilepsy)	Asia 495 per 100,000 persons
	51.32 per 100,000 persons	Europe 457 per 100,000 persons
	Incidence	North America 5,097 per 100,000 persons
	49.06 per 100,000 persons	South America 934 per 100,000 persons
		Incidence (active epilepsy)
		Africa 78.39 per 100,000 person-years
		Asia 37.56 per 100,000 person-years
		Europe 43.87 per 100,000 person-years
		North America 42.48 per 100,000 person-years
		South America 119.78 per 100,000 person-years
Parkinson disease	Prevalence	Prevalence
	315 per 100,000 persons	Asia 337 per 100,000 persons
	Incidence	Africa 77 per 100,000 persons
	Females 36.5 per 100,000 person-years	North America/Europe/Australia 1,398 per 100,000 persons
	Males 65.5 per 100,000 person-years	South America 1,046 per 100,000 persons
Cerebral palsy	Prevalence	Region specific analysis not performed
	221 per 100,000 live births
Traumatic brain injury	Incidence (all age groups)	Incidence (all age groups)
	211.35 per 100,000 persons	Asia 380.35 per 100,000 persons
		Australia 414.56 per 100,000 persons
		Europe 227.74 per 100,000 persons
		North America 167.87 per 100,000 persons
Hydrocephalus	Prevalence (infants)	Region specific analysis not performed
	135 per 100,000 persons
Spina bifida	Prevalence	Prevalence
	46.20 per 100,000 persons	Africa 78.81 per 100,000 persons
		Asia 66.36 per 100,000 persons
		Australia 48.11 per 100,000 persons
		Europe 66.23 per 100,000 persons
		North America 35.72 per 100,000 persons
		South America 30.37 per 100,000 persons
Brain tumors	Incidence	Region-specific analysis not performed
	10.82 per 100,000 person-years
Cervical dystonia	Prevalence	Prevalence
	4.98 per 100,000 persons	Japan 2.52 per 100,000 persons
		Europe 6.71 per 100,000 persons
Duchene muscular dystrophy	Prevalence (males)	Region specific analysis not performed
	4.78 per 100,000 persons
Spinal cord injury	Incidence (excluding prehospital mortality)	Incidence (excluding prehospital mortality)
	2.88 per 100,000 persons	Europe/Asia/Australia 2.24 per 100,000 persons
	Incidence (including prehospital mortality)	North America 4.23 per 100,000 persons
	5.13 per 100,000 persons
Huntington disease	Prevalence	Prevalence
	2.71 per 100,000 persons	Asia 0.40 per 100,000 persons
	Incidence	North America/Europe/Australia 5.7 per 100,000 persons
	0.38 per 100,000 persons
Multiple sclerosis	Meta-analysis not performed	Meta-analysis not performed
Source: Jette N, Pringsheim T. Technical report for the Public Health Agency of Canada and the Neurological Health Charities of Canada: systemic reviews of the incidence and prevalence of neurological conditions. Ottawa, Canada: Public Health Agency of Canada; 2013 Neurology 2014;83(18):1661–1664.

Primary brain and other central nervous system tumors of children and adolescents diagnosed in the United States in 2009–2013
	Age at diagnosis (Years)
	0–14 Y			0–19 Y			0–4 Y
	5-year total	Annual average	Rate	5-year total	Annual average	Rate	5-year total	Annual average	Rate
Neuroepithelial tumors	12,303	2,461	4.04	15,363	3,073	3.74	4,880	976	4.88
Astrocytoma
Pilocytic	2,999	600	0.98	3,645	729	0.89	1,065	213	1.06
Diffuse	792	158	0.26	1,083	217	0.26	308	62	0.31
Anaplastic	275	55	0.09	375	75	0.09	69	14	0.07
Unique variant	343	69	0.11	461	92	0.11	89	18	0.09
Glioblastoma	467	93	0.15	692	138	0.17	113	23	0.11
Oligodendroglioma	110	22	0.04	203	41	0.05	19	4	0.02
Anaplastic	–	–	–	28	6	0.01	–	–	–
Astrocytic	70	14	0.02	127	25	0.03	19	4	0.02
Ependymal tumors	961	192	0.31	1,230	246	0.30	496	99	0.50
Malignant glioma, NOS	2,385	477	0.78	2,737	547	0.67	931	186	0.93
Choroid plexus	336	67	0.11	390	78	0.09	239	48	0.24
Other neuroepithelial tumor	30	6	0.01	34	7	0.01	–	–	–
Neuronal/mixed neuronal-glial tumors	1,091	218	0.36	1,631	326	0.40	276	55	0.28
Pineal tumors	139	28	0.05	183	37	0.04	57	11	0.06
Embryonal tumors	2,295	459	0.75	2,544	509	0.62	1,188	238	1.19
Medulloblastoma	1,466	293	0.48	1,642	328	0.40	554	111	0.55
PNET	287	57	0.09	334	67	0.08	176	35	0.18
Atypical teratoid/rhabdoid tumor	353	71	0.11	359	72	0.09	316	36	0.32
Other embryonal histologies	189	38	0.06	209	42	0.05	142	28	0.14
Tumors of cranial and spinal nerves	809	162	0.27	1,218	244	0.29	277	55	0.28
Nerve sheath tumors	809	162	0.27	1,216	243	0.29	277	55	0.28
Tumors of meninges	500	100	0.16	1,012	202	0.24	151	30	0.15
Meningioma	273	55	0.09	615	123	0.15	59	12	0.06
Mesenchymal tumors	162	32	0.05	210	42	0.05	80	16	0.08
Primary melanocytic lesions	–	–	–	–	–	–	–	–	–
Other neoplasms related to the meninges	58	12	0.02	177	35	0.04	–	–	–
Lymphomas and hematopoietic neoplasms	79	16	0.03	120	24	0.03	17	3	0.02
Lymphoma	29	6	0.01	58	12	0.01	–	–	–
Other hematopoietic neoplasms	50	10	0.02	62	12	0.02	–	–	–
Germ cell tumors and cysts	635	127	0.21	918	184	0.22	156	31	0.16
Germ cell tumors, cysts, and heterotopias	635	127	0.21	918	184	0.22	156	31	0.16
Tumors of sellar region	1,415	283	0.47	3,472	694	0.83	169	34	0.17
Tumors of the pituitary	743	149	0.24	2,655	531	0.63	30	6	0.03
Craniopharyngioma	672	134	0.22	817	163	0.20	139	28	0.14
Unclassified tumors	912	182	0.30	1,419	284	0.34	318	64	0.32
Hemangioma	308	62	0.10	534	107	0.13	115	23	0.12
Neoplasm unspecified	585	117	0.17	862	172	0.21	194	39	0.19
All other	19	4	0.01	23	5	0.01	–	–	–
Total	16,653	3,331	5.47	23,522	4,704	5.70	5,968	1,194	5.98
Abbreviations: NOS, not otherwise specified. Source: CBTRUS (Central Brain Tumor Registry of the United States); NPCR (National Programs of Cancers). 2016 Society for Neuro-Oncology Epidemiology and End Results program. Oxford Journals NEURO ONCOL, October 1, 2016;18(suppl 5). Note: Annual average cases are calculated by dividing the five-year total by five. Rates are per 100,000 and are age-adjusted to the 2000 US standard population.

Primary brain and other central nervous system tumors of children and adolescents diagnosed in the United States in 2009–2013
	Age at diagnosis (Years)
	5–9 Y			10–14 Y			15–19 Y
	5-yr total	Annual average	Rate	5-yr total	Annual average	Rate	5-yr total	Annual average	Rate
Neuroepithelial tumors	3,914	783	3.85	3,509	702	3.41	3,060	612	2.85
Astrocytoma
Pilocytic	1,017	203	1.00	917	183	0.89	646	129	0.60
Diffuse	227	45	0.22	257	51	0.25	291	58	0.27
Anaplastic	97	19	0.10	109	22	0.11	100	20	0.09
Unique variant	118	24	0.12	136	27	0.13	118	24	0.11
Glioblastoma	163	33	0.16	191	38	0.19	225	45	0.21
Oligodendroglioma	41	8	0.04	50	10	0.05	93	19	0.09
Anaplastic	–	–	–	–	–	–	18	4	0.02
Astrocytic	22	4	0.02	29	6	0.03	57	11	0.05
Ependymal tumors	229	46	0.23	236	47	0.23	264	54	0.25
Malignant glioma, NOS	893	179	0.88	561	112	0.55	352	70	0.33
Choroid plexus	48	10	0.05	49	10	0.05	54	11	0.05
Other neuroepithelial tumor	–	–	–	–	–	–	–	–	–
Neuronal/mixed neuronal-glial tumors	313	63	0.31	502	100	0.49	540	108	0.50
Pineal tumors	37	7	0.04	45	9	0.04	44	9	0.04
Embryonal tumors	699	140	0.69	408	82	0.40	249	50	0.23
Medulloblastoma	684	117	0.57	328	66	0.32	176	35	0.10
PNET	54	13	0.06	47	9	0.05	47	9	0.04
Atypical teratoid/rhabdoid tumor	25	5	0.02	–	–	–	–	–	–
Other embryonal histologies	25	5	0.03	21	4	0.02	20	4	0.02
Tumors of cranial and spinal nerves	259	52	0.26	273	55	0.27	409	82	0.38
Nerve sheath tumors	259	52	0.26	273	55	0.27	407	81	0.38
Tumors of meninges	112	22	0.11	237	47	0.23	512	102	0.47
Meningioma	61	12	0.06	153	31	0.15	342	68	0.32
Mesenchymal tumors	43	9	0.04	39	8	0.04	48	10	0.04
Primary melanocytic lesions	–	–	–	–	–	–	–	–	–
Other neoplasms related to the meninges	58	12	0.02	44	9	0.04	119	24	0.11
Lymphomas and hematopoietic neoplasms	34	7	0.03	28	6	0.03	41	8	0.04
Lymphoma	–	–	–	–	–	–	29	6	0.03
Other hematopoietic neoplasms	23	5	0.02	–	–	–	–	–	–
Germ cell tumors and cysts	168	34	0.17	311	62	0.30	283	57	0.26
Germ cell tumors, cysts, and heterotopias	168	34	0.17	311	62	0.30	283	57	0.26
Tumors of sellar region	483	97	0.48	763	153	0.74	2.057	411	1.91
Tumors of the pituitary	175	35	0.17	538	108	0.52	1.912	382	1.77
Craniopharyngioma	308	62	0.30	225	45	0.22	145	29	0.13
Unclassified tumors	219	44	0.22	375	75	0.36	507	101	0.47
Hemangioma	66	13	0.07	127	25	0.12	226	45	0.21
Neoplasm unspecified	150	30	0.15	241	48	0.23	277	55	0.26
All other	–	–	–	–	–	–	–	–	–
Total	5,189	1,038	5.12	5,496	1,099	5.34	6.869	1,374	6.38
Abbreviations: NOS, not otherwise specified. Source: CBTRUS (Central Brain Tumor Registry of the United States); NPCR (National Programs of Cancers). 2016 Society for Neuro-Oncology Epidemiology and End Results program. Oxford Journals NEURO ONCOL, October 1, 2016;18(suppl 5). Note: Annual average cases are calculated by dividing the five-year total by five. Rates are per 100,000 and are age-adjusted to the 2000 US standard population.