Table 5.

Clinical studies on the relationship between PHE and neurologic functions after ICH.

Quantitative methods	Study	Design	No. of patients	Functional outcome measures	Imaging modality	Median ICH volume on admission (mL)	Time phase for PHE quantitation	Findings
Absolute PHE volume	Volbers et al. [100]	Retrospective	292	90-day mRS	CT	17.7	Peak PHE volume	The high peak volume of PHE was an independent predictor of the worse outcome on day 90.
	Volbers et al. [20]	Retrospective	220	mRS at discharge	CT	22.8	Within 12 h	The high peak PHE volume predicted a poor discharge outcome.
	Ozdinc et al. [175]	Retrospective	106	30-day mortality	CT	2.14 vs. 18.73 for survivors and nonsurvivors within 30 d after ICH onset	On days 1-12	The absolute area of the perihematomal edema but not the absolute volume of the perihematomal edema was an independent indicator of mortality at 30 days.
	Nawabi et al. [99]	Retrospective	811	90-day mRS	CT	47	Within 12 h	An increase in early PHE volume did not increase the probability of a poor outcome in OAC-ICH but was independently associated with poor outcomes in NON-OAC-ICH.
	Shirazian et al. [176]	Prospective	1,089	30-day mortality, 90-day mRS	CT	22.5	Within 48 h	The absolute increase in PHE within 48 hours after ICH was associated with increased mortality and worse functional outcomes.
	Appelboom et al. [177]	Prospective	133	Discharge outcome (mRS)	CT	Less than 30	Within 24 h	The effect of absolute PHE volume on functional outcome after ICH depended on the size of the hematoma, with only patients with smaller hemorrhages showing poorer results with worse PHE.
	Loan et al. [178]	Prospective	342	Death or dependence (mRS) one year after ICH	CT	48	Within 3 days	The high volume of perihematomal edema did not predict a poor outcome.
PHE growth	Lv et al. [179]	Prospective	233	3-month mRS	CT	13.4	From baseline to 24 hours	Early expansion of PHE was associated with poor outcomes.
	Ye et al. [116]	Prospective	197	90-day mRS	CT	12.7	From baseline to day 3	An increase in PHE volume > 7.98 mL from baseline to day 3 may lead to a poor outcome on day 90 after ICH.
	Grunwald et al. [180]	Retrospective	115	90-day mortality or poor functional outcome (mRS > 2)	CT	11.3 vs. 36.9 for patients with deep and lobar ICH	From baseline to 24 h and 72 h	PHE 72 hours was associated with poor functional outcomes after deep ICH, while PHE 24 hours was associated with mortality for deep and lobar ICH.
	Urday et al. [109]	Retrospective	139	90-day mRS	CT	19	PHE expansion rate between admission and 24-hour post-ICH	A faster PHE expansion rate 24 hours after ICH predicted a worse outcome.
	Murthy et al. [181]	Prospective	596	90-day mRS	CT	15	Within a period of 6 to 72 hours after the onset of ICH	The absolute increase in PHE during the first 72 hours after ICH was associated with worse functional outcomes, particularly with basal ganglia ICH and hematomas < 30 mL.
	Hurford et al. [136]	Prospective	1,028	90-day mRS	CT	13.7	From onset to 72 hours	An increase in EED in the first 72 hours was independently associated with decreased functional outcomes at 90 days.
	Wu et al. [115]	Prospective	861	6-month mortality	CT	14	The first 72 hours	A higher EED than expected was associated with mortality at 6 months.
	Venkatasubramanian et al. [21]	Prospective	27	Barthel index, mRS, and extended GCS scores at 3 months	MRI	33.6	From admission to 48 h	The growth of edema volume was correlated with a decrease in neurologic status at 48 hours, but not with a functional outcome.
rPHE volume	Sykora et al. [139]	Prospective	38	Early neurologic deterioration	CT	20.63	48-72 h after ictus	rPHE independently predicted early neurologic deterioration.
	Arima et al. [138]	Prospective	270	Death or dependency at 90 days	CT	NA	On day 3	Both absolute PHE and rPHE predicted death or dependency at 90 days.
	Gebel et al. [182]	Prospective	142	12-week mRS or 30-day mortality	CT	12.2	Within 3 hours after the onset of ICH and then 1 and 20 hours later	rPHE independently predicted a poor 3-month functional outcome. Absolute edema volume predicted neither mortality nor functional outcome.
	Staykov et al. [110]	Retrospective	219	In-hospital mortality	CT	35.7	Increase in absolute PHE between days 1 and 3, initial rPHE	An increase in absolute PHE but not rPHE between days 1 and 3 was significantly predictive of in-hospital mortality.

Abbreviations: PHE: perihematomal edema; ICH: intracerebral hemorrhage; OAC: oral anticoagulant; NON-OAC-ICH: nonoral anticoagulation-related intracerebral hemorrhage; rPHE: relative perihematomal edema; EED: extension distance; mRS: modified Rankin scale; GCS: Glasgow Coma Scale; CT: computed tomography; MRI: magnetic resonance imaging.